GWEN IFILL: And we turn to the presidential campaign.
Republicans go to the polls tomorrow in three places: Maryland Washington, D.C., and battleground Wisconsin.
Mitt Romney focused exclusively on Wisconsin today, campaigning alongside popular Congressman Paul Ryan, who endorsed him last week.
MITT ROMNEY (R): I believe if we have leaders that are willing to tell the truth and live with integrity, who understand how to lead and understand how the world and the economy works, and are willing to draw on the patriotism and willingness to sacrifice of the American people, that we will rise to the occasion, overcome our challenges and keep America as it has always been: the hope of the Earth. And I intend to be one of those leaders with your vote tomorrow.
GWEN IFILL: Romney also earned the backing of Wisconsin's Republican Senator Ron Johnson, who like Ryan said it's time for the party to rally behind a nominee.
SEN. RON JOHNSON, R-Wisc.: Gov. Romney is the person to lead our party, to lead our nation.
GWEN IFILL: With 42 delegates up for grabs in tomorrow's winner-take-all contest, a Wisconsin victory could boost Romney's mathematical chances of capturing the nomination.
Wisconsin's GOP voters are clustered in the conservative Milwaukee suburbs, where Romney has been outspending Rick Santorum 4-1. As a result, Romney has held a comfortable lead in every recent poll. He's also expected to do well in Maryland and Washington, D.C., which also hold primaries tomorrow.
Santorum remains Romney's chief rival. And he said he plans to remain in the race. He's been campaigning heavily in Wisconsin over the past several days. Newt Gingrich, who spent today in Maryland, vowed yesterday to fight on until Romney officially wins enough delegates to clinch the nomination.
NEWT GINGRICH (R): He has to earn the 1,144. We're not going to concede it to him.
GWEN IFILL: As Romney has stepped up his attacks on President Obama, the Democrats have begun to push back.
VICE PRESIDENT JOSEPH BIDEN: I think that -- I think Governor Romney is a little out of touch.
This is about the middle class. And none of what he's offering does anything. It's just a return to the old policies.
GWEN IFILL: And at a White House news conference today, the president said his plan is to ignore his Republican critics -- for now.
PRESIDENT BARACK OBAMA: It's still primary season for the Republican Party. They're going to make a decision about who their candidate will be. It's worth noting that I first arrived on the national stage with a speech at the Democratic convention that was entirely about American exceptionalism and that my entire career has been a testimony to American exceptionalism. But, you know, I will cut folks some slack for now, because they're still trying to get their nomination.
GWEN IFILL: After tomorrow, the next voting doesn't occur until April 24, in Delaware, Connecticut, New York, Rhode Island and, critically, in Santorum's home state of Pennsylvania.
So what is at stake tomorrow in Wisconsin? Susan Page, Washington bureau chief of USA Today, is just back from a reporting trip there. And Craig Gilbert of The Milwaukee Journal Sentinel joins us from Milwaukee.
Craig, let's start with you.
We've heard that there are five polls out now showing Romney with a pretty substantial lead. Is everything as it appears?
CRAIG GILBERT, The Milwaukee Journal Sentinel: Well, he does have a steady lead.
I wouldn't call it a commanding lead. It's somewhere between five and 10 points. And it hasn't really moved around very much. I mean, it's been -- when the candidates came here, they stepped into a very strange and unique environment, where the recall fight over Wisconsin's governor has really dominated everything.
And I think it's made it difficult for Rick Santorum to kind of punch through that aura of inevitability that Mitt Romney reacquired in the last few weeks.
GWEN IFILL: Tell me about Wisconsin. Who are the Romney voter there in the GOP primary and who are the Santorum voters?
CRAIG GILBERT: Well, Santorum's strength has been in rural areas and Romney's strength has been in suburban, more upscale areas.
And when you look at Wisconsin, there is a big rural vote, but really the heart of the Republican electorate in Wisconsin are in these counties that ring Milwaukee where you have -- that generally deliver massive turnouts and margins for Republicans in general elections.
One of these counties, Waukesha, gave John McCain his biggest raw net vote margin of any county in the northern United States in 2008. These counties really tend to determine the outcome of Republican primaries. And I would expect to see Romney do pretty well in that part of the state.
GWEN IFILL: Susan, are conservative voters like that, are they beginning to coalesce around Romney, as he would like to say that they are, or are they still kind of flirting with Rick Santorum?
SUSAN PAGE, USA Today: Well, Craig and I were both at the Waukesha County GOP dinner Saturday night.
GWEN IFILL: What a nice time, way to spend your Saturday night.
SUSAN PAGE: I think there were some basketball games going on too. But we didn't see those.
GWEN IFILL: Yes.
SUSAN PAGE: And in talking to voters there, voters who were inclined toward Santorum, I found several of them saying I like Santorum, but it's time to get this race over.
There's concern that this battle, this continuing primary is hurting the Republican prospects in November. And all the Republicans I talk to, their number one goal is getting rid of Barack Obama, denying him a second term, even if it means supporting Romney, who might not necessarily be their first choice.
GWEN IFILL: And are there messages on television there as harsh as they have been or is it all beginning to tail off at this stage?
SUSAN PAGE: Well, there are no positive -- I can't remember the last time I saw a positive ad for anybody. Santorum is up with a new negative ad that likens Romney to Obama in his positions. So there's a lot of -- there continue to be a lot of negative ads. I think if you're watching the airwaves, there's just nobody to feel very good about.
GWEN IFILL: Craig, there have been a couple of big endorsements in the last several days. It feels like they're being rolled out in a pretty regular way, but for Wisconsin voters especially, the senator, Republican senator Ron Johnson, and also Paul Ryan last week.
Does it matter, these endorsements?
CRAIG GILBERT: I think it's been helpful.
I mean, Paul Ryan has sort of been Mitt Romney's inseparable escort around the state since Friday. He's very popular in the state. And both Ryan and Johnson, you know, kind of give the conservative seal of approval in Wisconsin to Mitt Romney. And so I think that has been helpful.
GWEN IFILL: And have we seen any sign of competition coming from Newt Gingrich or Ron Paul in Wisconsin?
CRAIG GILBERT: Not much.
They really haven't been a factor. One thing that struck me about the polls in Wisconsin is if you look at the personal popularity ratings of both Santorum and Romney, they're almost identical. And they're both fairly positive among Republican primary voters, but I think that tells you that Romney's advantage really is about this sense that he's the nominee and that it's time for Republicans to move on to the general election phase.
GWEN IFILL: It does seem to be a pretty steady drumbeat at this stage. Is there pressure being brought -- independent of the endorsements of the other guy, is there pressure being brought from the Republican establishment or from any Republicans to get Santorum to step aside?
SUSAN PAGE: Well, I think that there are a lot of senior Republicans who would like Santorum to step aside.
But that's really a decision that Santorum gets to make. And some concern that if you push him in that direction, maybe he will resist or make it harder for him to get out. The big question is, if he loses tomorrow in Wisconsin, as we expect, does he choose to hang on for three weeks for his home state of Pennsylvania or does he give it up then?
If you listen to what he said today, he says he's in it all the way to the convention in Tampa.
GWEN IFILL: There doesn't seem to be a lot of incentive to get out at this point. But I wonder to what degree this makes it more difficult for Mitt Romney to do what he says he wants to do, which is start focusing on President Obama.
SUSAN PAGE: I think if Mitt Romney wins Wisconsin tomorrow night -- and we expect him also to win D.C. and Maryland -- that Wednesday morning starts the general election.
I think that Mitt Romney, the reporters who cover him in this campaign and the Obama campaign move on to a general election strategy, whatever Rick Santorum or Newt Gingrich or Ron Paul does.
GWEN IFILL: In a state like Wisconsin, Craig, where President Obama did pretty well in 2008 -- we have seen, according to polls in Susan's newspaper and other places, that the president is doing pretty well in a theoretical head to head.
Is that something which is going to -- when the race changes to talking about the general in which it's over in Wisconsin or is it still competitive?
CRAIG GILBERT: No, I think the Republican Party certainly thinks it's competitive.
I think, you know, fact that it was so close in 2000 and 2004, and the fact that the Republican Party had such an historically successful election in 2010 in Wisconsin makes Wisconsin a very tempting blue state target for the Republicans, not to mention the fact that the chairman of the Republican National Committee is from Wisconsin. They will go after Wisconsin.
And I think that lead will tighten as Republicans rally around Mitt Romney, assuming he's the nominee. And then we will find out in the summer and the early fall if the Republicans can hang in there in Wisconsin.
GWEN IFILL: What about the recall movement, the effort to recall the Republican governor? Is that mobilizing Republicans?
CRAIG GILBERT: Absolutely. It's mobilizing everybody.
I mean, it's the recall that consumes and angers and exasperates and inspires and energizes people. Nothing else is a close second. So both sides are getting kind of a trial run, organizationally, in this recall election that's coming up in June. And we're going to see, you know, a very polarized state turn out in extreme numbers in November as a result.
GWEN IFILL: And, finally, Susan, the battle zone poll I was referring to in your newspaper, it shows the president doing -- opening up kind of a theoretical lead over these Republicans. What is that about? What is driving that?
SUSAN PAGE: We have done five of these polls since October. And for the first time, a significant lead for any candidate, this time for the president, and it's due to shifts in support among women, especially women under 50, now by 2-1 supporting President Obama over Mitt Romney.
So this debate that we've had over about the last month that involves contraception and Planned Parenthood, some of these other issues, it seems clear that that's reverberating with a lot of women who are moving to the president's side. Mitt Romney now has a 19-point gender gap with women. There are not enough men in America to elect you if you have a 19-point gender gap with women. That is something that campaign is going to have to address.
GWEN IFILL: We will be watching to see how they do that.
Susan Page with USA Today and Craig Gilbert of The Milwaukee Journal Sentinel, thank you both very much.
SUSAN PAGE: Thank you.