

While Mr. Biden has made no decision about his future, people familiar with his thinking say, he hasn't ruled out a bid for the White House. If he runs, that could set up a titanic battle between two of the party's most prominent figures.

Allies say Vice President Biden, visiting the USS Freedom in Singapore last month, could win the 2016 nomination. Associated Press

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One step under discussion by Biden backers is to form a political action committee he would use to funnel money to other Democratic candidates, which could build goodwill for a possible White House bid, people familiar with the talks said. Meanwhile, Mr. Biden is preparing to attend a Democratic event in Iowa, which traditionally holds the first nominating contest, and to raise money this week for the Democratic governor of New Hampshire, the state that holds the first primary.


Many prominent Democrats believe that Mrs. Clinton would be so heavily favored in a presidential primary that Mr. Biden and other party hopefuls wouldn't even contest the nomination were she to run. A recent poll in New Hampshire showed Mrs. Clinton leading Mr. Biden and other possible Democratic candidates by upward of 50 points.

"I don't see Biden and Hillary running against each other," said David Axelrod, a senior strategist in both of President Barack Obama's presidential campaigns and who worked for Mrs. Clinton's New York senatorial bid in 2000. "I would be shocked to see that materialize."



Mr. Biden raised $11.3 million in his 2008 presidential campaign before dropping out of the race after the Iowa caucuses, according to the Center for Responsive Politics.

"There's definitely a path forward for him" even if Mrs. Clinton decides to run, said Larry Rasky, who worked on Mr. Biden's two previous presidential bids, in 1988 and 2008.

A senior aide to Mr. Biden said: "The vice president is focusing on being vice president and making the president's second term as productive as possible. Any talk of other future plans is complete speculation."

Biden allies believe he could run on some of the accomplishments Mr. Obama notched over two terms. If the economic recovery continues, Mr. Biden could run on the basis that he was a partner in combating the recession. Unemployment hit 10% in the first year of Mr. Obama's term and as of July was down to 7.4%.

"My guess is it would be a legacy campaign, continuing to build on the success they've had in the administration,'' Mr. Rasky said.

Mr. Biden finds himself in an unusual spot: a sitting vice president who would be a distinct underdog in a race to win his party's support.

Over the past half century, vice presidents who ran for president invariably captured their party's nomination. Al Gore did so in 2000; George H.W. Bush beat back a challenge from then-Sen. Bob Dole in 1988. Hubert Humphrey prevailed in 1968, and Richard Nixon easily won the GOP nomination in 1960.

The last sitting vice president to fail to win the nomination was Alben Barkley, who served under Harry Truman and lost out in 1952 to Adlai Stevenson. Mr. Barkley was 74, and his age was cited as a reason for his defeat.

Mr. Biden will be 73 when the 2016 election rolls around, but his handicap isn't age so much as the formidable presence of Mrs. Clinton, analysts say. A Clinton candidacy would have historic implications. If the former first lady and secretary of state won, she would break a gender barrier much as Mr. Obama broke a racial barrier in 2008.

"He's in the shadow of Hillary Clinton, and he always has been," said Robert Dallek, a presidential biographer.

So far, Mr. Biden has left open the possibility of running, telling GQ magazine this year that "I can die a happy man never having been president of the United States, but it doesn't mean I won't run."

Mr. Biden's itinerary shows he has an eye on the states holding early contests. On Thursday, he will headline a fundraiser for New Hampshire Gov. Maggie Hassan, the state's Democratic leader. Next month, he will speak at the annual steak fry hosted by Sen. Tom Harkin, an Iowa Democrat.

A Biden aide described the Iowa appearance as "a longstanding commitment after the vice president was unable to attend last year."

But others saw campaign considerations at work. Mike Gronstal, a Democrat who is the majority leader in the Iowa Senate, said of Mr. Biden: "He's got lots of important duties as vice president of the United States, and he decided to come out to Sen. Harkin's steak fry. I couldn't imagine how you wouldn't read something into that." Mr. Gronstal said it is too early for him to commit to a candidate.

One Democratic official who is close to Mr. Biden said of his inner circle: "Everyone involved in his world is engaged in taking all the steps that make sense to prepare for a run, if he does run."

If Mrs. Clinton and Mr. Biden run, Mr. Obama would stay out of the race, the official said, and express support for both. People with knowledge of the dynamic say Mr. Obama has signaled to others in the White House that he sees both as equals.

"There's some consideration given to making sure that the vice president's people aren't upset by anything," the Democratic official said. Mr. Obama's aides, for example, told Mr. Biden's team that the president's joint interview with Mrs. Clinton earlier this year with the CBS program "60 Minutes'' was prompted by his appreciation for the job she did as secretary of state, not about setting her up for a White House bid.

In private conversations, Mr. Biden's advisers are talking about steps to prepare for his possible entry into the race. A political action committee, these people say, would allow Mr. Biden to raise and disburse money to favored candidates in the 2014 midterm elections, cementing ties to influential Democrats around the country in advance of a possible presidential bid.

The political action committee would be similar to the "leadership PACs" created by members of Congress. It could accept individual donations of up to $5,000, said the people familiar with the talks. Mr. Biden also could use it to cover the cost of political travel, such as his coming trips to Iowa and New Hampshire, election law experts said.

If they decide to run, Mrs. Clinton and Mr. Biden would need to announce their intentions in 2014, political analysts said. But Mrs. Clinton is thought to have the luxury of being able to wait longer than Mr. Biden, because a super PAC called Ready for Hillary already is organizing and raising money for her potential candidacy.

The pro-Clinton group has picked up some marquee talent from Mr. Obama's campaign team, including two experts in grass-roots organization, Jeremy Bird and Mitch Stewart.

"Everybody is ready to go," said Harold Ickes, a top strategist in Mrs. Clinton's 2008 campaign and an informal adviser to the Ready for Hillary PAC. "There are people who are ready not only to raise money for her but to give handsomely…But no one is doing anything until she gives a positive nod."

Some Biden backers say that if he ran and notched some early victories, he could crack the image of Mrs. Clinton as an invincible candidate.

Sara Riley, a lawyer from Cedar Rapids, Iowa, who volunteered for Mr. Biden's 2008 campaign, said that if Mrs. Clinton hasn't learned from her third-place showing in the state in 2008, Mr. Biden could seize a chance to build early momentum.

But Mr. Biden has hit hurdles in his own White House campaigns. He dropped out of the 1988 race amid accusations he plagiarized a speech and law-school paper. In 2008, Mr. Biden placed fifth in Iowa's caucuses, garnering 23 delegates, compared with 737 won by Mrs. Clinton. He soon quit the race.

Write to Peter Nicholas at peter.nicholas@wsj.com, Carol E. Lee at carol.lee@wsj.com and Colleen McCain Nelson at colleen.nelson@wsj.com