Republican presidential hopeful Rick Santorum told diners in Carnegie, Pa., on Wednesday that May "looks very, very good" for his campaign, but admitted the Keystone State primary later this month is a "must win" if he has any hope of remaining in the race.
Pennsylvania's April 24 contest will not be an easy victory for Santorum, who Tuesday night watched front-runner Mitt Romney sweep the Maryland, District and Wisconsin primaries and leap even further ahead of him in the race for convention delegates.
Romney now has 652 delegates, more than half of the 1,144 needed to lock up the nomination, according to RealClearPolitics. Santorum has only 229 delegates, which means he would need to win more than 70 percent of the remaining delegates to prevail over Romney.
Pennsylvania has 72 delegates up for grabs, but even though Santorum grew up outside Pittsburgh and represented the state in Congress for 16 years, Romney is far better financed and organized and stands a solid chance of beating him.
The two candidates are running even in the polls, but Romney will soon flood the airwaves with ads attacking Santorum, which could undercut Santorum's standing with the religious conservatives and blue-collar Republicans who have favored Santorum.
"Santorum's campaign needs to perform well here," said Vince Galko, a Pennsylvania political strategist who served as Santorum's campaign manager during his failed 2006 bid for a third Senate term.
Galko said Romney will have a fight on his hands, despite what the polls are showing and the advertising blitz Romney plans.
"Santorum has built up a strong political network and has touched a lot of lives in the state," Galko said. "It's more than just campaign advertising. He has devoted a big part of his life to the people here. That's got to count for something."
Santorum's campaign, however, has been handicapped not only by the organization and money behind Romney, but by the growing chorus of prominent Republicans who want him to drop out so that GOP voters can coalesce around the former Massachusetts governor.
Among those pressuring Santorum is Tom Ridge, Pennsylvania's former Republican governor who endorsed Romney last month.
Sen. John McCain, the 2008 Republican nominee, on Wednesday added his name to a list of establishment Republicans that includes former Florida Gov. Jeb Bush and former President George H.W. Bush. McCain told CBS News he believes Santorum should realize "it's time for a graceful exit."
Princeton University history and public affairs professor Julian Zelizer told The Washington Examiner he believes Santorum is remaining in the race not to win the nomination, but to solidify his credentials as the voice of the Republican Right and perhaps position himself for another run in 2016 if Romney can't beat Obama.
"At this point Santorum is playing a game where he keeps himself in the public eye for his own political future and so maybe next time, he can talk about how long he lasted in this race," Zelizer said.
Romney, who is heading to Pennsylvania following an appearance before the nation's newspaper editors Wednesday in Washington, completely ignored his primary opponents and focused instead on Obama.
"This November, we will face a defining decision," he said. "Our choice will not be one of party or personality. This election will be about principle. Freedom and opportunity will be on the ballot."