Mitt Romney, who prides himself on "wallowing in the data" before making tough decisions, now confronts an unforgiving mathematical landscape of delegate counts, polls, and popular vote tallies that suggest the odds are overwhelmingly against his presidential bid.
John McCain's sweep on Super Tuesday of winner-take-all states in the Northeast and big states such as California gave him a commanding lead in delegates - 703 of the 1,191 needed to clinch the nomination, compared with 293 for Romney and 190 for Mike Huckabee, according to an Associated Press tally.
With 499 total delegates up for grabs through March 4, Romney would have to win more than 80 percent of them to catch McCain, assuming the Arizona senator won none. And, even if Huckabee won them all, he would still trail McCain. Dividing the total among the three candidates makes over taking the front-runner more difficult still.
While Romney hopes to do well in several of the states voting over the next month, his chances of drawing even with McCain appear slim because the vast majority of the delegates will be awarded in states without winner-take-all contests, forcing the candidates to split their winnings. In addition, moderate Republican electorates in some of the states also appear to favor McCain.
McCain's strategist, Charlie Black, released an analysis yesterday that flatly concluded: "The math is nearly impossible for Mitt Romney to win the nomination."
Romney, however, plans to soldier on, as does Huckabee.
Peppered with questions about the delegate count, Romney's traveling press secretary, Eric Fehrnstrom, dismissed the notion that the campaign cannot be rescued and said Romney's plan now hinges on rolling up big margins in the delegate-rich Ohio and Texas primaries on March 4.
Ohio, he said, is struggling with many of the same economic problems as Michigan, which Romney won last month largely on the strength of his business experience. Fehrnstrom said Texas has a very conservative primary electorate that should respond well to Romney's message of economic, social, and national security conservatism.
But those states, with a combined 222 delegates, are not winner-take-all, meaning Romney will have to share any winnings there with McCain and Huckabee.
Romney plans to campaign this week in Kansas and Washington, which hold caucuses on Saturday and will award a total of 73 delegates. Those states should be friendly territory because Romney has done well in contests where he can leverage his organizational and financial muscle, Fehrnstrom said. He will also campaign today in Maryland, eyeing its primary on Tuesday.
McCain, meanwhile, is looking to cement his front-runner status, finish off his rivals before the March 4 contests, and start uniting the fractured GOP behind him. National polls of Republicans show McCain with a commanding lead, 41 percent to Romney's 24 percent and Huckabee's 21 percent, according to the most recent Gallup poll, conducted just before Super Tuesday.
Yesterday, McCain canceled a planned trip to a national security conference in Germany this weekend to campaign instead.
"I think we've got to wrap this thing up as quickly as possible," McCain told reporters in Phoenix before flying to Washington, D.C., where he and Romney are scheduled to speak to a key gathering of conservative activists today. Huckabee is set to address the group, the Conservative Political Action Conference, on Saturday.
McCain also began airing three TV ads in Virginia, a winner-take-all state with 60 delegates that votes Tuesday. Virginia, with a demographic split between prosperous, moderate suburbs in the north, rural conservative turf in the south, and a large military population around Norfolk, offers opportunities for all three candidates.
"I'm presuming Virginia will be the big battle of next Tuesday," Black said.
McCain's aides said they go into the other Tuesday primaries, in Maryland and the District of Columbia, with momentum. They have 53 delegates combined.
Huckabee said yesterday that he needs to do well in those upcoming contests, but declared himself the "true conservative" alternative to McCain and pointed out that he won core Republican states in the South on Tuesday. "It puts me in the race," the former Arkansas governor said on MSNBC.
But if McCain continues to widen his delegate lead, pressure is likely to build on Huckabee and Romney to step aside for the good of the party.
Some political specialists cautioned that Romney must consider not only his present candidacy, but the future of his political career. If the Democrats capture the White House this year and Romney wants to run again in 2012, he cannot afford to alienate his party once it has coalesced around McCain, said Wayne Lesperance, a political scientist at New England College.
"A calculation is going to have to happen very soon in his campaign as to whether or not his continuing on is in his best interest in the long run," Lesperance said.
The resurgence of Huckabee on Super Tuesday - he won five states to Romney's seven and McCain's nine - also poses problems for Romney, because the two are competing for the support of social conservatives. Fehrnstrom downplayed the dynamic, saying Huckabee benefited from the support of evangelical voters who will make up a smaller proportion of the electorate in upcoming states.
But Lesperance said that even in those states, evangelicals account for a large enough portion of the electorate to frustrate Romney. In Ohio, for example, he said Huckabee could draw about 10 or 15 percent of the conservative Christian vote that might otherwise go to Romney.
"I think if the race were between McCain and Romney, then the scenarios might play out a little more favorably towards Romney," Lesperance said.
"So as long as Huckabee is in the race, it's difficult to imagine a scenario where Romney could be successful."
Still, Romney's staff put on a brave face yesterday.
Staff members gave him a round of applause when he showed at the campaign's North End headquarters, where he thanked them for their work and huddled with key aides to plot campaign strategy.
Fehrnstrom described morale as very upbeat.
"We're number two in delegates," he told reporters. "We feel very good about our chances going forward."
Sasha Issenberg of the Globe staff contributed to this report from Phoenix.