WASHINGTON -- The relatively rosy March employment report is posing a political dilemma for prospective Republican presidential candidates: Should they stay focused on a sharp economic critique of the Obama presidency as the economy improves, or broaden the lines of attack and risk diluting the anti-Obama message?

President Barack Obama, just days from officially announcing his re-election bid, touted the numbers Friday at a visit to a UPS facility in Maryland: 230,000 private sector jobs added in March, 1.8 million in the last 13 months, an unemployment rate down a full point in the past four months.

"And the last time that happened was during the recovery of 1984," he said. Mr. Obama didn't say it, but that's the year Ronald Reagan cruised to re-election.

The president's potential 2012 rivals have been less optimistic. Former Massachusetts Gov. Mitt Romney, in a USA Today opinion piece this week, accused the president of "passive acquiescence" in the face of crippling unemployment. Former Minnesota Gov. Tim Pawlenty, on Fox News Tuesday, predicted the U.S. is heading for a double-dip recession.

"Each job that is added in America is a good thing," Mr. Pawlenty posted on his Facebook page Friday. "However, in the bigger picture, I remain concerned that out-of-control government spending is undermining our long-term economic health."

Republican strategists are divided over how to respond to the brightening economy. Former United Nations Ambassador John Bolton, who is mulling a White House run, says candidates focusing on economic and deficit issues are leading the party into a dead end. Other candidates, such as former House Speaker Newt Gingrich and former Pennsylvania Sen. Rick Santorum, have broadened their critiques to focus on foreign policy or social issues.

Whit Ayres, a Republican political consultant, said the trend might be positive for Mr. Obama, but in 50 years, only one president, Mr. Reagan, was re-elected with unemployment over 5.6%, and even then, it was 7.5%, slightly below where the rate is projected to be in November 2012.

"I'm afraid some people are becoming conditioned to unemployment rates above 8%," Mr. Romney said Friday in North Las Vegas, where he was meeting with struggling homeowners. "The idea that we celebrate 8.8% -- I mean, my gosh!"

But Republican economists say GOP candidates need to adjust their message now or risk looking like they're cheering for an economic reversal. Kevin Hassett, economic policy director at the conservative American Enterprise Institute, said the message should shift to balancing the budget, reining in the size of government and revamping the health-care law.

"The only thing Republicans can do is shine a bright light on what Obama has done and see if voters find it distasteful, because they're not going to be able to say, 'Look at the terrible job market Obama gave us,'" Mr. Hassett said. "First, he started off with a terrible job market. Second, it's improving."

Ray Fair, a Yale University economist who has used economic modeling to predict election outcomes, said job-market trends are more important than the actual jobless rate. Franklin Roosevelt won re-election in 1936 in part because a burst of growth gave voters enough optimism to look beyond the 17% unemployment rate. His model currently predicts Mr. Obama winning 52% of the popular vote next year.

Republican economist Douglas Holtz-Eakin, an adviser to Sen. John McCain in the 2008 campaign, said employment would still be an issue for the president come Election Day, but the budget fight "will be the defining issue."

Candidates must go beyond cutting spending for its own sake and begin articulating a policy vision for a reshaped federal government, he said.