White House adviser Plouffe: Romney campaign 'built on a tripod of lies'

White House senior adviser David Plouffe on Sunday said Mitt Romney's presidential campaign is "built on a tripod of lies."

"I don't think we've ever seen a presidential campaign, ever, that's built on a foundation of lies," he said on ABC's "This Week."

"They'll have to answer for their own motivations," Plouffe said, refusing to speculate on strategy but maintaining that the GOP nominee’s campaign has deliberately lied.

Plouffe highlighted three particular policy disagreements where he accused the Romney team of being dishonest:  their claim that Obama removed the work requirement from welfare, charging Obama with "raiding Medicare" to pay for his signature healthcare legislation, and what he described as the "'we can't build it' nonsense."

Obama's team has often expressed frustration with the phrase the GOP turned into a convention theme, which comes from a speech the president made in Virginia over the summer.

"If you’ve got a business, you didn’t build that. Somebody else made that happen," Obama said in the speech, after referencing the Internet, roads and other government-backed infrastructure that support American businesses.

Republicans and the Romney campaign quickly piled on, arguing Obama was taking credit away from entrepreneurs and hardworking Americans. "We built it" became a popular chant at the Republican convention.

Plouffe on Sunday defended the president’s remark, saying that Republicans were knowingly using it out of context. "The point he was trying to make was things like education, infrastructure...are things we do together," Plouffe said of Obama’s comment.

The president has pushed back hard on the GOP ticket’s welfare and Medicare arguments, saying both are not based on fact, but the Romney campaign stands by them.

GOP vice presidential candidate Paul Ryan has made Medicare a staple in his stump speech since joining the campaign last month, and brought it up in his acceptance speech at the Republican National Convention.

"Seven hundred and sixteen billion dollars, funneled out of Medicare by President Obama," Ryan said. "Ladies and gentlemen, our nation needs this debate. We want this debate. We will win this debate."

Democrats say that the $716 billion were reductions to Medicare’s projected growth over the next ten decades and came from trimming waste and fraud, not cutting benefits. 

Plouffe dismissed Ryan's claim but said Team Obama is in agreement that "this is a debate we need to have.”

“We're anxious to have it," said Plouffe.

The Romney campaign on Sunday pushed back at Plouffe, accusing the Obama team of trying to distract attention from the president’s economic record.

"President Obama's problem is that the truth about his abysmal record hurts,” said Romney spokesperson Ryan Williams, in a statement. “Americans aren't better off today than they were four years ago. Twenty three millions Americans are struggling for work and more people are in poverty than ever before under the Obama economy.” 

“The Romney-Ryan plan for a stronger middle class will accomplish what President Obama has been unable to do -- grow the economy and create good jobs," Williams said.

This story was updated at 2:13 p.m. to include reaction from the Romney campaign.