After winning 11 straight primary and caucus victories against New York Sen. Hillary Clinton, Illinois Sen. Barack Obama, the current Democratic front-runner in the race to the White House, appears to be encroaching on Clinton territory in Ohio and Texas.
The most recent ABC News/ Washington Post poll showed him closing in on Clinton's once hefty lead in both states, and polls conducted since show an even tighter race.
Clinton has also received pressure from prominent Democrats and Obama backers to withdraw if she does not perform well in Texas and Ohio, Tuesday.
Withdrawal 'Up to Sen. Clinton'
"Well, I think that'll be up to Sen. Clinton," said Obama. "But if we do well in Texas and Ohio, I think the math is such where it's going to be hard for her to win the nomination, and they'll have to make a decision about how much longer they want to pursue it."
"I would assume that there are going to be people who want to bring this to an end one way or another, because [Arizona Sen.] John McCain's out there — the reputed Republican nominee — and he's given a little bit of a free pass."
Huge crowds greeted Obama in Westerville, Ohio, Sunday. There was a decent amount of overflow and a few hundred left outside, unable to squeeze in.
Earlier in the day, a smaller event took place in the outskirts of Appalachia where he talked up "green jobs," but told the small audience it would be a challenge to turn the economy around.
To many political experts, Clinton's performance in delegate-rich states like Ohio and Texas has the potential of deciding the future of her campaign. Even former President Clinton has admitted that losing one could mean the end of his wife's presidential run.
Obama says he's not taking any chances. "Remember New Hampshire," he reminded reporters last week, recalling his surprising defeat in the New Hampshire primary.
But Clinton, feeling a newfound surge in energy after raising more than $35 million in February — Obama has reportedly raised more than $50 million — has shown no signs of giving up.
Obama: Clinton 'a Lot More Aggressive' Lately
Recently, the Clinton campaign has increased its attacks on Obama, and the candidate has kicked up her rhetoric.
"For some people, this election is about how you feel," she told a crowd at a rally in Westerville, Ohio. "It is about speeches. That is not what it is about for me. It is about solutions."
Clinton sparked media attention last week after her campaign aired a new ad in Texas that suggests the senator is better able to handle a national crisis.
"It's 3 a.m. and your children are safe and asleep," a deep, ominous voice explains in the ad, while a camera pans over the faces of sleeping children. "But there's a phone in the White House, and it's ringing. Something's happened in the world. Your vote will decide who answers the call."
The Obama campaign accused the Clinton campaign of "fear-mongering."
"I think she has got a little desperate toward the end of this campaign," Obama told "Nightline's" Terry Moran, while campaigning in Ohio. "[She] has been a lot more aggressive in her negative attacks.
"As I've pointed out, we've actually had a pretty significant moment in the last several years, that called people's judgment into question. And that was the war in Iraq."
Regarding the Iraq War, this weekend, Clinton told reporters that if she runs against McCain, she will "put forth my lifetime of experience. Sen. Obama will put forth a speech he made in 2002."
Obama disagrees with that characterization. "I was in the midst of a U.S. Senate race," he said. "It wasn't simply a speech. It was an ongoing opposition."
Obama Welcomes the 'Experience' Debate
On the question of experience, Obama welcomes the contrast between him and Clinton, who has repeatedly described herself as someone who is "tested" and "ready."
"I think the question is, how do you know any president is ready?" Obama said. "[Until] you're president, you haven't made these decisions."
"What people can take a look at is how I exercised judgment on key foreign policy questions over the last several years," he said. "And I think they can have confidence. ... More often than not, I have shown judgment that was superior to some of these people who are claiming much lengthier experience."
As part of her proven experience, Clinton has highlighted her visits to more than 80 countries, her time spent in the White House and her service on the Senate Armed Services Committee.
"Look, I've lived overseas," said Obama. "I have family overseas. I have served on the Senate Foreign Relations Committee."
As for Clinton's experience in the White House, Obama is dubious. "It is true that I've not lived in the White House," he said. "Although, one of the tough things about Sen. Clinton's campaign has been the degree to which she takes credit for good things that happened and doesn't take credit for bad things that happened."
I Don't Get Rattled'
Obama believes that his "matter of temperament" best prepares him for the White House.
"One of the things that I've known about myself for a long time," he said, "is that, in difficult or stressful moments, I don't get rattled And I don't get rattled during campaigns. I don't get rattled when things are up ... and I don't get too low when things are down."
"Part of the problem that we've seen historically when presidents make bad decisions is either they're ideologically driven — I would argue that that's what happened with George Bush," he said. "Or, oftentimes, it's driven by politics."
But Obama's critics point to Tony Rezko, a Chicago real estate developer, as a reason to question Obama's brand of politics.
Rezko — who has raised a lot of money for Obama over the years — goes on trial this week on corruption charges. Rezko has ties to many politicians, but it is a real estate deal Rezko participated in with Obama in 2005 that enabled the senator to purchase his current home, that has brought a lot of scrutiny to the candidate's campaign.
For Obama, who has called himself a reformer and touted his judgment, some voters might ask how could he enter into this transaction with a longtime contributor who, at that time, was known to be under investigation for corruption?
"I've already said that that was a mistake, even though it was completely above board," said Obama. "Because he had been a contributor, I shouldn't have entered into any real estate transaction with him."
Obama says he has returned all contributions from Rezko or the people associated with him. As for Rezko, he has pleaded not guilty to the corruption charges issued against him.
The Clinton campaign has said that Obama's mea culpa isn't enough and has called on the senator to release more information related to Rezko.
"Any of us — if you go through my entire career — or any of our careers, we're going to make mistakes occasionally."
Lessons Learned From 'SNL'
Finally, Obama brought his attention to "Saturday Night Live," which, lately, has portrayed the media as fawning over the senator, while dismissing his female rival.
Obama took issue with his portrayal on the show. "As Michelle pointed out, it showed that I needed to smile more, apparently, because he always looks very grim," he said with a laugh.