Let's go to the race for the white house. Things are heating up on the campaign trail. Mitt romney telling donors yesterday, that president obama is diminishing the office. This comes one day after... See More
Let's go to the race for the white house. Things are heating up on the campaign trail. Mitt romney telling donors yesterday, that president obama is diminishing the office. This comes one day after the president took a personal job at the gop candidate. It's "your voice, your vote." And david muir is on the trail and joins us from new port, kentucky. David? Reporter: Hey, amy. The romney campaign going on the offensive on two months. On medicare, they say this is a debate they welcome. But something equally as potent, the president's likability. This morning, president obama is defending vice president joe biden, after biden ignited that fiery war of words, while criticizing mitt romney. The president speaking out overnight, in an interview with "entertainment tonight." What joe biden was talking about, is again, an example of a substantive argument, a substantive issue that the american people should be concerned about. And his phrasing is a distraction from what it is saying. Reporter: But that phrasing got him into trouble, when he took on romney, who has criticized those new rules, meant to watch over the big banks. Unchain wall street. They're going to put y'all back in chains. We don't spend a lot of time worrying about the chatter. The country's not as divided or obsessed with gaffes or some stray remark as washington is. Reporter: But the romney campaign had already pounced, calling it a sign of a desperate presidency. The president's campaign is all about division and attack and hatred. Reporter: Overnight in ohio, romney's running mate, paul ryan, continued to punch. The president used to say, we're not blue states or red states. We're the united states of america. This is the most partisan time we've had in memory. Reporter: A concerted effort by the romney campaign to go after his strongest asset in the polls, his likability. Not if michelle obama would have her way. Her first time on the campaign season. Joking about her trip to the state fair. Pork chop and beer. He's so pleased with himself. Reporter: And overnight, ann romney, defending her husband, on his decision to release only two years of his tax returns. It will just give them more ammunition. There's nothing we're hiding. We've had a blind trust for how many years. We don't even know what's in there. Reporter: Ann romney, sticking to the argument we've heard from the governor himself, before. Anything more than two years simply gives their opponents, as ann romney just put it, more ammunition. Amy, back to you. More to come. David muir, thanks so much.
This transcript has been automatically generated and may not be 100% accurate.