AUDIE CORNISH, HOST:
From NPR News, this is ALL THINGS CONSIDERED. I'm Audie Cornish.
ROBERT SIEGEL, HOST:
And I'm Robert Siegel. Today is the day Mitt Romney has been waiting for. Rick Santorum is pulling out of the race for the Republican presidential nomination, leaving the field essentially clear for Romney. Santorum made the announcement to his supporters in Gettysburg, Pennsylvania.
RICK SANTORUM: We made a decision to get into this race at our kitchen table against all the odds, and we made a decision over the weekend that while this presidential race for us is over, for me, and we will suspend our campaign effective today, we are not done fighting.
SIEGEL: A year ago, in the early Republican debates, Rick Santorum was at one end of the stage looking like an also-ran. Other candidates rose and fell. And then the voting began, and Santorum emerged as the chief threat to frontrunner Mitt Romney. NPR's Mara Liasson is here with me now to consider what was and what might have been. And Mara, is it fair to say that Santorum went farther than perhaps even he expected to go in this race?
MARA LIASSON, BYLINE: Absolutely. And he has said as much. You know, he started driving around in a pickup truck in Iowa with him and maybe one aide. He, as you said, was on the fringes of the debate stage. He couldn't get a word in edgewise. He often was really frustrated at that. But then he went on to be the number one opponent to Mitt Romney. And I think he never expected this, and I think most people credit him with an incredibly resourceful, scrappy insurgent campaign. He did take on the establishment, and he went a very long way.
SIEGEL: Was Santorum just the last man standing or perhaps a measure of Romney's weakness, or did he represent something bigger than all that?
LIASSON: Well, I think he represented something bigger than just the last man standing. I think part of his success was a function of Romney's weakness and his failure to win over the white working class, which is a growing segment of the Republican primary electorate, to win over social conservative voters. Those were Santorum's two key groups. Every state that had more than 50 percent evangelical voters in the primary was won by Rick Santorum. Every state that had fewer than 50 percent self-identifying evangelical voters Romney won.
And I do think that there are two wings of the Republican Party. Romney needs to unify them now. He hasn't been able to so far. And there really never was a candidate who could do both, who could appeal to the Tea Party conservative activist base while at the same time getting the establishment behind him, raising the money and setting up the national organization you need to be a major candidate. Rick Perry was supposed to be that candidate. He didn't turn out to be. But yes, I think what Rick Santorum represents is this activist base of the Republican Party that doesn't identify with the establishment.
SIEGEL: Well, given, though, that he has this appeal to the party's most loyal voters, was there a moment when Santorum could have won? Might he have pushed Mitt Romney aside?
LIASSON: I think he needed to have won in Michigan, to beat Romney in his home state. He needed to have won in Ohio - big important battleground. Maybe if he had found a better way to balance the social conservative issues with his economic message on manufacturing, he could have done better. But who knows? He never had the resources to really mount a strong â strong enough challenge to Romney.
SIEGEL: Why now? Why did he drop out now?
LIASSON: Well, I think we have to take him at his word. Family considerations were part of it. His daughter had just been in the hospital, but also he was facing a potential loss in his home state of Pennsylvania on April 24th. That would have been completely devastating to him. And I think it would have undermined his future in politics.
SIEGEL: Speaking of his future, of course much depends on whether the Republicans win or lose the White House, but what is his future?
LIASSON: Well, he could be in a Romney Cabinet. He certainly will be a conservative social issue leader in the Republican Party. 2016, he could run again. He'll have a heck of a lot of competition if does that, though.
SIEGEL: OK. Thanks, Mara.
LIASSON: Thank you, Robert.
SIEGEL: That's NPR's Mara Liasson. Transcript provided by NPR, Copyright NPR.