Hillary Clinton won primaries in Florida, North Carolina and Ohio, the night's most contested prize, as her rival, Sen. Bernie Sanders, struggled to get the boost he needed to try to close the gap in the race for the Democratic presidential nomination. 
 
 Clinton also won a close contest in Illinois and was holding an extremely small margin in Missouri, with nearly all of the votes counted. With those contests so close, neither candidate will gain a significant edge from them in the race for delegates to the Democratic nominating convention this summer. Clinton's three big victories, by contrast, will give her a major gain. 
 
 “We are moving closer to securing the Democratic Party nomination and winning this election in November,” Clinton told supporters here, and she quickly moved to an attack on the Republican she expects to face in that election, Donald Trump, whom she accused of offering “bluster and bigotry.” 
 
 “Our next commander in chief has to be able to defend our country, not embarrass it; engage our allies, not alienate them,” she said. 
 
 “When we hear a candidate for president call for rounding up 12 million immigrants, barring all Muslims from entering the United States, when he embraces torture, that doesn't make him strong — it makes him wrong.” 
 
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 Clinton barely mentioned Sanders, the independent senator from Vermont, except to briefly congratulate him for running a “vigorous campaign.” 
 
 If Sanders was chastened by the results, he didn't let it show while speaking to rapturous supporters in Phoenix. 
 
 “Do not settle for the status quo when the status quo is broken,” he said in a speech in which he showed no sign of easing up on Clinton. He once again attacked her vote in favor of the war in Iraq and demanded she release the transcripts of lucrative speeches to Wall Street firms. 
 
 Sanders had worked aggressively over the last week to expand a beachhead in the nation's industrial states after his upset victory in Michigan last week exposed new vulnerabilities for Clinton. 
 
 That set up Ohio as a key contest, where both candidates campaigned extensively and spent large amounts on television advertising. Clinton's victory there will go a long way toward solidifying her margin in the delegate race and reassuring her supporters. 
 
 Clinton's victory in North Carolina continued her sweep through the South, where black voters make up a big share of the Democratic electorate. And her decisive win in Florida, where she took nearly two-thirds of the vote, will net her a large majority of the state's 246 delegates to the Democratic convention — the third-largest delegation after California and New York. 
 
 The wins mean Clinton will significantly expand her already large lead among delegates to this summer's convention, building a margin of roughly 300 delegates over Sanders, without counting the roughly 400 so-called superdelegates who back her — party leaders and elected officials who automatically get convention votes. 
 
 After Tuesday, the math looks increasingly daunting for her rival, who now would need a series of very big victories in big states to catch up with Clinton's growing lead in the delegate race. 
 
 That does not, however, mean she has clinched the nomination. Under the Democrats' rules, which allocate delegates proportionately to each candidate's vote, Clinton probably won't be able to do that until the primary season ends in California in June. 
 
 In the Michigan upset last week, frustration among Midwestern Democrats with some of the free-trade policies Clinton has backed over the years, as well as with the Wall Street institutions whose recklessness helped push the nation into recession in 2007, emerged as a significant liability for the former secretary of State. 
 
 That anger shaped the campaigns in the three Midwestern states. Polls had indicated that all three could have close contests, and after the big miss by pollsters in Michigan, all of whom predicted a Clinton victory, both campaigns were wary of predictions. 
 
 Sanders' attacks on corporate America, particularly on trade, clearly connected with many voters. 
 
 “I believe in his change,” said Sanders supporter Mark Russell, 59, who stopped to vote in the Clintonville neighborhood of Columbus, near Ohio State University, on his way to work at Goodwill Industries. 
 
 “I believe that right now we're run by corporations,” he said. “It's not an even playing field, and it counts against us. I believe that he can do something about that. He's the only one that's really talking in that direction.” 
 
 Yet Sanders' effort to translate that sort of sentiment into votes came up short this time. 
 
 Clinton continues to do well with voters like Tampa resident Zachary Hines, 26, who value her years of preparation. 
 
 “She's the most prepared and experienced candidate to run for president in modern history,” said Hines, who works as a marketing director for a theater company. “I'm very excited to vote for the first woman president.” 
 
 Exit polls suggested voters were more confident in Clinton's agenda, with 77% in Ohio saying her policies were realistic, as opposed to 58% saying the same about Sanders' proposals. The divide was even bigger in Florida, where only 46% of voters expressed confidence that the Sanders agenda was realistic, according to exit polling conducted for the major television networks and the Associated Press. 
 
 Female voters came out in force for Clinton on Tuesday. She won 67% of them in Florida and 58% of them in Ohio, according to the exit poll. She also dominated with nonwhite voters in both states, winning 73% of them in Florida and 63% in Ohio. Seniors supported her by a margin of nearly 4 to 1 in both states. 
 
 Clinton had been eager to avenge a Michigan loss that some operatives attributed to poor strategic decisions and resource deployment by a campaign that had grown complacent after public polls that proved wildly misleading. 
 
 To ensure she did not repeat that defeat, Clinton redoubled her focus on the Midwest. 
 
 The former secretary of State, who has locked up almost every major national union endorsement, mobilized her labor supporters and stepped up her opposition to the Trans Pacific Partnership, the trade deal negotiated by President Obama that is reviled by unions. ||||| Hillary Clinton Hillary Diane Rodham ClintonSanders poised to announce presidential campaign: report Transparency advocate group releases trove of hacked Russian documents Arson suspected at DC restaurant associated with 'Pizzagate' conspiracy MORE took a huge step toward clinching the Democratic presidential nomination on Tuesday with big victories in the swing states of Florida and Ohio. 
 
 Tuesday’s results also made a November showdown between Clinton and Republican front-runner Donald Trump Donald John TrumpStone: 'I’ve never had any discussion' with Trump about a pardon White House: Trump will move forward on wall 'with or without' Dems Pelosi after Stone indictment: 'What does Putin have on the president'? MORE more likely after the businessman won Florida’s winner-take-all GOP primary. 
 
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 The blemish for Trump was a loss in Ohio, where the state’s governor, John Kasich, won his first victory of the 2016 campaign — a win he desperately needed. 
 
 Still, Trump took home all 99 of Florida’s GOP delegates and in the process ended rival Marco Rubio Marco Antonio RubioThe Hill's 12:30 Report — Stone indicted in Mueller probe | Says he's not guilty | Day 35 of shutdown | FAA briefly halts flights into LaGuardia A crowded 2020 presidential primary field calls for ranked choice voting Omar, Tlaib come under fire from GOP MORE’s presidential campaign in his home state. The senator suspended his campaign shortly after 8 p.m., telling his supporters that it “is not God’s plan that I be president in 2016 or maybe ever.” 
 
 But the biggest victories went to Clinton. The former secretary of State’s defeat of Bernie Sanders Bernard (Bernie) SandersSanders poised to announce presidential campaign: report On The Money: Trump agrees to end shutdown without wall funding | Senate quickly clears short-term funding measure | House to vote tonight | Federal workers could get back pay within days | Dems take victory lap Shutdown ends without funding for Trump’s border wall MORE in Florida was widely expected, but her prize in Ohio was far from a sure thing. 
 
 “This was another super Tuesday for our campaign,” Clinton told cheering supporters in Florida. “Thank you, Florida, thank you, North Carolina and thank you, Ohio.” 
 
 Clinton then pivoted to Trump, criticizing his call for a wall on the U.S.-Mexico border, his proposed ban on Muslims entering the country and his call for the use of torture against suspected terrorists. 
 
 “When we hear a candidate for president call for rounding up 12 million immigrants, banning all Muslims from entering the United States, when he embraces torture, that doesn’t make him strong, it makes him wrong,” Clinton said. 
 
 “We should be bringing down barriers, not building walls,” she added. “You know, to be great, we can’t be small. We can’t lose what made America great in the first place.” 
 
 In Florida, Clinton won 65 percent of the vote compared to 33 percent for Sanders, with 99 percent of precincts counted. 
 
 The Sunshine State was the biggest prize of the night for Democrats, awarding 214 pledged delegates, and Clinton’s win means she will pad her already substantial delegate lead. 
 
 The Sanders campaign upset Clinton last week in Michigan and had hoped to steal another state away in Ohio with its anti-trade, anti-Wall Street message. 
 
 The results in the two swing states will do much to calm Democrats who have been unnerved by Sanders’s successes against Clinton, which had given ammunition to critics calling her a flawed candidate. 
 
 Clinton on Tuesday also added a victory in North Carolina, continuing a sweep of the South built on her popularity among African-American voters. She won in Illinois as well. 
 
 The wins move Clinton closer to winning the 2,383 delegates she needs to win the Democratic race, and could put her all but out of reach for the Vermont senator. 
 
 By late Tuesday evening, Clinton had 1,410 delegates, according to The Associated Press, which includes unbound superdelegates, and she was likely to add to that tally by the end of the night by winning delegates in the Missouri primary, which remained too close to call. 
 
 Things weren’t quite as clear-cut on the Republican side, though Trump underlined his status as the party’s front-runner with a significant win in Florida and victories in North Carolina and Illinois. 
 
 Trump won about 46 percent of the Florida vote, compared to 27 percent for Rubio. Ted Cruz Rafael (Ted) Edward CruzA crowded 2020 presidential primary field calls for ranked choice voting Bennet: Washington politics have been 'tyrannized' by Freedom Caucus, Cruz NASA space center asking employees to volunteer to clean bathrooms during shutdown MORE had 17 percent. 
 
 "We have something happening that actually makes the Republican Party the biggest political story anywhere in the world," the celebrity billionaire said in Palm Beach, Fla. 
 
 "Millions of people are coming out to vote. ... I think we're going to have a great victory." 
 
 The Florida result was a stunning defeat for Rubio that will raise questions about his political future. The senator decided against running for reelection to pursue his White House bid and will now return to the upper chamber as a lame duck. 
 
 In his speech to supporters but without naming Trump, Rubio decried the nasty rhetoric and personal insults that have dominated Republicans’ 2016 campaign. 
 
 “While this may not have been the year for a hopeful or optimistic message about our future, I still remain hopeful and optimistic about America,” he said. “I ask the American people, do not give in to fear. Do not give into frustration.” 
 
 Missouri also hosted a GOP contest Tuesday but remained too close to call definitively with nearly 100 percent of the vote in on both sides. Both Clinton and Trump were ahead by less than 1 percentage point. Sanders and Cruz, who was right behind Trump, could both call for recounts. 
 
 Kasich’s win in Ohio was good news for those who want to prevent Trump from clinching the nomination before the party’s national convention this July in Cleveland. 
 
 Trump would need to win about 60 percent of the remaining delegates to get to the 1,237 he needs. 
 
 Cruz has been calling for the other candidates to drop out of the race to give him an opportunity to go after Trump one-on-one. 
 
 On Tuesday, it appeared he would have to wait longer for such a scenario after Kasich’s win in Ohio. 
 
 Updated at 1:44 a.m. ||||| The Fix's Philip Bump explains why a contested convention still might not be a realistic path forward for Bernie Sanders. (Peter Stevenson/The Washington Post) 
 
 With the Democratic presidential nomination system working the way it does, there are essentially two possible outcomes: A candidate will either win in a blowout, or he or she will need superdelegate votes to gain a majority. 
 
 The reason for this is simple: Fifteen percent of all of the Democratic delegates are unbound superdelegates. So unless you have about an 18 percentage-point lead among delegates by the time the voting wraps up, you'll need some superdelegates to put you over the top. This makes the difference between a close race and a blowout a little murky — which can be advantageous to the underdog. 
 
 Right now, Hillary Clinton has about a 10 percentage-point delegate lead over Bernie Sanders. (For comparison: Barack Obama's pledged delegate lead was only about four percentage points by the end of the 2008 race.) The current margin is not likely to change much between now and the end of the contest, with the two likely to play to a draw in California, Clinton to win big in New Jersey and D.C., and Sanders to triumph in smaller states between now and the end of the race. For it to change significantly in Sanders's favor, he'd need to do very, very well in California and New Jersey in particular, a promise that he has issued often and delivered rarely. 
 
 One of the things that Sanders has been very good at, though, is conveying a convincing depiction of a guy who's going to come from behind and win this thing, even as he has continued to trail badly or dropped further behind. During a news conference in Washington on Sunday marking the first anniversary of his campaign launch, Sanders insisted that the math above means that the Democrats were headed to a "contested convention," leveraging the now-common language of the ferocious (and unsettled) Republican contest to paint his own contest as similarly unsettled. 
 
 "It is virtually impossible for Secretary Clinton to reach the majority of convention delegates by June 14 with pledged delegates alone," he said. "She will need superdelegates to take her over the top at the convention in Philadelphia. In other words, the convention will be a contested contest." 
 
 That's true — mostly because, unlike in 2008, Sanders will contest it. Eight years ago, Clinton conceded the race before the convention, recognizing that trying to fight her way to victory on the convention floor was likely to fail, despite her having a slight lead in the popular vote. But Clinton realized the damage that could be done to the party — and perhaps herself — so she didn't. 
 
 Sanders doesn't share the former sentiment, as he has made clear. He was an independent until he decided to run for president, and his goal during his campaign has been to upend the system, into which a convention floor fight fits neatly. 
 
 But that doesn't mean he has any real shot at winning. 
 
 Sanders, like Clinton, needs superdelegates to win. Even if it were he who led by 10 percentage-points among pledged delegates, he'd need them. So let's consider his arguments for why they should give him their votes. 
 
 1 of 42 Full Screen Autoplay Close Skip Ad × Highlights from Bernie Sanders’s campaign, in pictures View Photos The senator from Vermont is Hillary Clinton’s rival in the contest for the Democratic presidential nomination. Caption The senator from Vermont is Hillary Clinton’s rival in the contest for the Democratic presidential nomination. June 14, 2016 Bernie Sanders arrives at the Capital Hilton to meet with Hillary Clinton in D.C. Matt McClain/The Washington Post Buy Photo Wait 1 second to continue. 
 
 The "momentum" argument 
 
 Back in the halcyon days of Sanders's "momentum," when he'd won seven of eight contests in a row, including a big win in Washington, his argument was that the momentum would propel him through the end of the voting in June, offering a compelling argument to superdelegates that the will of the party now rested with him, and that Clinton's early support was therefore negated. Then he lost five of the last six races — and Clinton's delegate lead returned to about what it was in the middle of March. The momentum was, as many had suspected, a function of several Sanders-favorable races clustered in a short window (as was the recent streak by Clinton). The race hadn't really changed at all. 
 
 Now, it seems, Sanders's argument will be that his strong performances at the tail end of the contest, including a win in California — coupled with close national polling — should provide the same motivation to superdelegates to embrace his candidacy. Sanders is who the party now wants to win. 
 
 There are a few flaws in that argument, including that Sanders's one-point deficit in the national Real Clear Politics polling average — which came right after those seven wins — has now widened to four points. The biggest problem for Sanders, though, is that, unlike on the Republican side, California isn't the last contest. The last contest for the Democrats is the D.C. primary, on June 14. And there is essentially no way that Clinton will lose that contest, given how strongly she has performed in places with large black populations. 
 
 Meaning that the last voting will almost certainly reinforce Clinton's dominance — while reminding superdelegates why Clinton has such a big lead: black voters. It is black voters who helped Clinton run up huge wins in New York and Maryland last week, on March 15 and in southern states before that. D.C. will almost certainly make that point once again, with emphasis. 
 
 The pledged delegate argument 
 
 On CBS on Sunday, Sanders insisted that his campaign might still win the majority of pledged delegates. "We need to win 65 percent of those votes," he said of the remaining total. "The states coming up are favorable to us." 
 
 The problem for Sanders is, as it has always been, that Democratic contests are all proportional. He needs to win every state by a wide margin to hit his goal. The other problem for him is that nearly half of the remaining delegates are in California. If he and Clinton essentially tie there — or even if he wins by five points, which polling suggests won't happen — he needs three-quarters of the delegates everywhere else to make up for it (including New Jersey and D.C.). 
 
 Could he win pledged delegates? Yes, in the sense that he could win the lottery. 
 
 Superdelegates should vote the way their states did 
 
 During the news conference, Sanders suggested that superdelegates had an obligation to reflect the will of the voters in their states. 
 
 "Those superdelegates in states where either Secretary Clinton or myself has won a landslide victory — those superdelegates ought to seriously reflect on whether they should cast their superdelegate vote in line with the wishes of the people of their states," he said. He notes Washington in particular, a state with 17 superdelegates and a state he won by a large margin. 
 
 We looked at this a few weeks ago. Mandating that superdelegates in a state back the candidate who won narrows Clinton's lead, but doesn't erase it. If you mandate that the superdelegates be divvied up proportionally, the margin for Clinton narrows further. But, in the same way that she still has a lead in pledged delegates because of proportional distribution, she has a lead with superdelegates, too. 
 
 So none of those arguments is terribly strong. But even if they were more solid, there's a simple rebuttal to Sanders for which he has offered no real response: He's trailing in actual votes by an insurmountable margin. 
 
 Before Clinton's big wins in New York and the Northeast, our fact-checkers pegged her actual vote lead at 2.4 million. She got nearly 300,000 more votes in New York, 250,000 in Maryland and 200,000 in Pennsylvania. Sanders won Rhode Island, clawing back 14,000 votes. But Clinton now has well over 3 million more votes than Sanders. 
 
 What Sanders is asking superdelegates to do is ignore that lead. His supporters have a surfeit of unsubstantiated explanations for this gap (such as voter fraud), but it's not complicated. Clinton leads because more people voted for her. In 2008, Obama led because of strategic delegate accumulation; that's not why Clinton leads now. 
 
 Sanders asks that superdelegates set aside that the choices of those voters — many or most of them black — because he did well in Washington and maybe is close in national polling. It's impossible to see whom that will convince. 
 
 It's true that Sanders and Clinton are headed to a contested convention, if Sanders wants it. That doesn't mean, as it would on the Republican side, that the outcome is up in the air. Sanders's campaign slashed its staff as it announced that, for the first time this year, it didn't crush Clinton in fundraising. For there to be a contested convention, Sanders would need to convince his base that he can win one — and therefore to keep funding his efforts through California. He's welcome to do that; they're welcome to keep giving. 
 
 But what's going to happen at that convention is not much of a mystery.
– Bernie Sanders didn't lose the Democratic race on Tuesday night, but with big wins for Hillary Clinton in Ohio and at least three other states, he lost the momentum from his surprise win in Michigan and fell further behind in the delegate count. Analysts say that although the senator plans to keep his campaign going, Clinton could now be impossible to catch. A roundup of coverage: Sanders is now more than 300 pledged delegates behind Clinton, which may be an insurmountable margin, reports Politico, which describes his candidacy as a "teetering Jenga pile of youth support, momentum, and access to online millions"—now minus the "buttressing block" of Ohio. Tuesday night's results were a huge setback for Sanders, who had been counting on wins in the Midwest to keep his candidacy viable, reports the New York Times, which notes that Clinton's delegate lead over Sanders is about triple the size of the lead Obama had over her at this stage in 2008. The Washington Post also declares the race all but over for Sanders, calling Ohio a "back-breaking blow" that makes it nearly impossible for him to catch Clinton—though he clearly "has both the determination and the resources to keep fighting," and his campaign has already "accomplished far more than almost anyone anticipated." Sanders would need a "series of very big victories in big states" to catch up at this point, the Los Angeles Times reports, but because of how delegates are allocated, Clinton is still unlikely to clinch the nomination before California votes in June. In her primary night speech, Clinton praised Sanders' "vigorous campaign," but her focus was Donald Trump. "When we hear a candidate for president call for rounding up 12 million immigrants, banning all Muslims from entering the United States, when he embraces torture, that doesn't make him strong, it makes him wrong," she said, per the Hill. "We should be bringing down barriers, not building walls," she continued. "You know, to be great, we can't be small. We can't lose what made America great in the first place." Sanders probably can't win, but he should definitely stay in the race, writes Timothy Egan in a New York Times op-ed, praising the Vermont senator for energizing young voters, forcing the Democratic party to pay attention to the "angry millions in the margins," and pulling Clinton to the left on issues like trade deals and Wall Street. By staying in the race, Sanders' ideas "will shape every part of the party platform, which will give Clinton what she lacks: a clear message," Egan writes. "Eventually, he'll endorse the woman he influenced, and Democrats will be the better for it."