But today, she revised her comments.
"I'm winning Catholic voters and Hispanic voters and blue collar workers and seniors -- the kind of people Sen. McCain will be fighting for in the general election," she said. "No, some call you swing voters -- but I call you Americans."
Democratic strategist Tad Devine suggested that the way the Democratic campaign wraps up could have a major impact on Election Day.
"The way this race ends, particularly the way Hillary Clinton treats him in the end, the way the loser loses, will determine whether the winner can actually win in November," Devine said.
But how the winner wins could be an issue, too.
Obama took what looked like a victory lap on Capitol Hill today, where he met with undecided superdelegates.
In an interview with NBC News, Obama said that assuming he wins the Oregon primary May 20, he will have won a majority of pledged delegates, which he called significant.
"That will be an important day," he said. "If at that point, we have the majority of pledged delegates, which is possible, then, I think we can make a pretty strong claim that we've got the most runs and it's the ninth inning and we've won."