NATIONAL NEWS (CNN) — Mitt Romney on Wednesday defended his blistering new attack lines against President Barack Obama's campaign, in which he hammers the president's re-election team for recent ads and the vice president's controversial statement the day prior.
"The president's campaign is all about division and attack and hatred," Romney said on CBS' "This Morning."
He later added: "The president seems to be running just to hang on to power. I think he'll do anything in his power to try and get re-elected."
His comments come after Romney used some of his harshest words yet against the president. While speaking at a campaign event in Ohio Tuesday, Romney faulted Obama for being "intellectually exhausted," and called on the president to "take your campaign of division and anger and hate back to Chicago and let us get about rebuilding and reuniting America."
Part of his frustration, he said, stemmed from a pro-Obama super PAC ad that linked Romney with the death of a cancer patient, an ad which Obama's campaign has yet to condemn, Romney said.
A spokesman for the Obama campaign responded to Romney's speech Tuesday, saying the Republican candidate seemed "unhinged."
"Gov. Romney's comments tonight seemed unhinged, and particularly strange coming at a time when he's pouring tens of millions of dollars into negative ads that are demonstrably false," said Obama campaign Press Secretary Ben LaBolt.
Also in the interview Wednesday, the presumptive GOP presidential nominee specifically pointed to Joe Biden's remarks Tuesday, when the vice president told a Virginia crowd that Romney's vision of Wall Street reform would cut back on regulations and put "y'all back in chains."
Romney's campaign quickly seized on the comment, calling it a "new low" in the campaign, while some conservatives on Twitter accused Biden of using racial undertones.
On Wednesday, Romney reiterated that Biden's comments are "demeaning to the nature of the process" and "diminish the White House" but did not elaborate further on what he took issue with in Biden's remark.
"I think I've expressed myself well enough. I think the American people had the same reaction, which is they listened to the vice president and they thought, again, an unfounded charge and a metaphor which is not uplifting, not uniting. But one which is once again a divisive attack," Romney said.
Biden later clarified the remarks at an event in Wytheville, Virginia, suggesting his comments were in reference to House Speaker John Boehner's use of the word 'unshackled' in talking about Ryan's House budget proposal.
"The last time these guys unshackled the economy, to use their term, they put the middle class in shackles. That's how we got where we are," said Biden.
"And I'm told that when I made that comment earlier today in Danville, Virginia, the Romney campaign put out a tweet. You know, tweets these days? Put out a tweet, went on the airwaves saying, 'Biden, he's outrageous in saying that,' I think I said instead of 'unshackled,' 'unchained.' 'Outrageous to say that," said Biden. "That's what we had. I'm using their own words. I got a message for them. If you want to know what's outrageous, it's their policies and the effects of their policies on middle class America. That's what's outrageous."
Romney also answered questions about his new running mate, Rep. Paul Ryan of Wisconsin, in the CBS News interview, further aligning himself with the House Budget chairman's policy.
"His campaign is my campaign now. We're on exactly the same page. My campaign has made it very clear," Romney said. His comments come after repeated questioning in recent days over how closely the two pair up on their budget plans, including their visions for Medicare.
Romney also joked about Ryan's reputation as an exercise junkie, specifically the congressman's penchant for P90X, an intense home workout program designed by Tony Horton.
"I have never tried that. I might have him show me how to do it someday," Romney said. "I get on the elliptical or treadmill. That's about it for me. That workout of his, he's in pretty good shape."
CNN's Rachel Streitfeld and Gregory Wallace contributed to this report.