WASHINGTON - Republican Mitt Romney dug in Wednesday on his charge that President Barack Obama's campaign is driven by "division and attack and hatred," criticism aimed at cutting into Obama's likeability and personal appeal with voters.
In some of his harshest words yet against the president, Romney said Obama was "running just to hang onto power, and I think he would do anything in his power" to remain in office. Romney's comments escalated an already acrimonious campaign fueled by negative and sometimes false advertisements, as well as personal insults from the candidates and their surrogates.
Obama's campaign said Romney's fresh assertions seemed "unhinged."
Romney replied: "I think unhinged would have to characterize what we've seen from the president's campaign."
"These personal attacks, I think, are just demeaning to the office of the White House," he added.
The latest rhetorical scuffle erupted Tuesday after Vice President Joe Biden told a largely black audience in Danville, Va., that Republicans would seek to "unchain Wall Street" and "put y'all back in chains" by loosening Wall Street regulations.
Biden later said he had meant to use the term "unshackled." But he did not apologize, and he mocked the Romney campaign for showing outrage.
In his interview Wednesday on "CBS This Morning," Romney said: "I can't speak for anybody else, but I can say that I think the comments of the vice president were one more example of a divisive effort to keep from talking about the issues."
Romney's onslaught comes as polls show Obama with a narrow lead over his Republican rival less than three months before the Nov. 6 election. On Saturday, Romney named Wisconsin Rep. Paul Ryan as his running mate, a pick aimed at energizing his party's conservative base.
Now Romney, straying from his campaign's efforts to stay singularly focused on jobs and the economy, is targeting Obama's greatest strength — his likeability.
Every major poll in the past two months has found Obama's favorability rating in positive territory, while Romney's languishes at about even or worse and has deteriorated in some recent surveys.
Some of Romney's efforts to chip away at Obama's likeability have focused on negative ads run by the president's campaign and a super political action committee supporting him. Priorities USA Action ran a commercial suggesting Romney was personally responsible for the death from cancer of the wife of a man who worked at a steel plant that was bought and subsequently shut down by Romney's venture capital firm, Bain Capital.
"If you look at the ads that have been described and the divisiveness based upon income, age, ethnicity and so forth, it's designed to bring a sense of enmity and jealousy and anger," Romney said Wednesday.
The Romney campaign has run its own negative ads, including one widely discredited by independent fact-checkers that accuses Obama of gutting welfare reform. Romney's team is also running an ad that criticizes Obama for raiding the Medicare trust fund, a charge the president's team labeled dishonest and hypocritical.
Romney was holding private fundraisers Wednesday in North Carolina and Alabama. The president was campaigning in Iowa on Wednesday, the final day of his three-day bus trip through the Midwestern swing state. First lady Michelle Obama was joining the president for their first joint campaign appearance since May.
Before Romney unleashed his striking criticism of the president's campaign, much of the White House race this week had focused on Ryan's austere budget proposals.
Obama's campaign was launching state-specific efforts to target lesser-known elements of Ryan's budget, expanding beyond its opposition to the Republican vice presidential candidate's Medicare overhaul.
The developing Obama strategy comes as Romney and Ryan make clear they plan to campaign aggressively on Medicare, not run away from it. In person and in a television ad, the Republicans argued Tuesday that Obama is the one who cut spending for Medicare to put money toward his divisive health care overhaul.
In states with large military and veteran populations — Florida, Ohio and Virginia among them — the Obama campaign plans to attack Ryan's proposed cuts for veterans' benefits and care, a campaign official said. The official was not authorized to discuss the campaign strategy publicly and requested anonymity.
In Colorado, Ohio and Iowa, the campaign sees opportunities to capitalize on Ryan's proposed cuts to clean energy industries that are taking hold in those states. The Obama team will argue that cutting those investments would essentially cede new energy technologies — and the jobs that could come with them — to countries like China, the official said.
In Nevada and several other states, the campaign plans to push the impact of Ryan's budget on education, citing estimates that it would cut 200,000 children a year from Head Start, an early education program, and reduce Pell grants for 10 million college students.
Obama's team may launch other paid advertising on elements of Ryan's budget soon. But for now, the campaign is focused on getting its message out in local media and directly to voters through its ample grass-roots network, which still trumps Romney's ground game in some states.
Despite ramping up new areas of attack, Obama's campaign is still eager to link Romney to Ryan's Medicare proposals, both on the national level and in battleground states with a significant number of voters over the age of 65, including Florida, Ohio, Iowa and Pennsylvania.
The president's pollsters wrote in a campaign memo that Ryan's Medicare proposals are a "game changer" in Florida, the battleground state with the most electoral votes up for grabs in November.
Ryan, interviewed on Fox News Channel, said he and Romney believe Medicare can be a winning issue for Republicans in the fall. "Absolutely, because we're the ones who are offering a plan to save Medicare, to protect Medicare, to strengthen Medicare," he said.
Ryan didn't say so, but the budgets he has written in the House both called for leaving in place the cuts to Medicare that he now criticizes. Romney has consistently favored restoring the funds, and his running mate said, "I joined the Romney ticket."
Obama campaign spokesman Danny Kanner criticized Ryan's answers, saying the Wisconsin congressman is "not ready for prime time."
"First, he attacked the president for the very same Medicare savings that he includes in his own budget," Kanner said in a statement. "In the same breath, he falsely claimed that the Romney-Ryan budget protects Medicare — in fact, their plan would end Medicare as we know it, leaving seniors with nothing but a voucher in place of the guaranteed benefits they rely on today."
The Obama campaign released a web video Wednesday that declares Romney and Ryan "plan to end Medicare as we know it." It features news commentators and liberal analysts such as economist Paul Krugman declaring that Ryan's House Republican budget would mean millions of older Americans would be unable to afford health care.
The video declares that Romney has lied about Obama's record on Medicare, and says Obama's proposal cuts payments to Medicare providers but offers more benefits to Medicare participants.
Romney and the Republican National Committee planned to release a new Spanish language TV ad Wednesday highlighting Obama's economic policies. Romney's campaign didn't say where it would run or how much money they plan to spend on the spot.
Associated Press writers Kasie Hunt in Columbus, Ohio, and Jim Kuhnhenn in Washington contributed to this report.