Washington (CNN) -- The fight to define Paul Ryan is getting more heated by the day. But days after defending against an offensive against his running mate, Mitt Romney's campaign appears to be mounting a counteroffensive.
President Barack Obama's re-election campaign launched a full frontal assault on the House Budget Committee chairman almost immediately after Republican challenger Mitt Romney named the seven-term congressman from Wisconsin as his running mate Saturday morning.
The Obama campaign and fellow Democrats instantly attacked Ryan over his budget, terming it a "radical plan" that would benefit the rich at the detriment to the middle class, and they highlighted his proposals to alter Medicare, which they said would "end Medicare as we know it."
The Romney campaign has fired back, accusing the president of hurting the popular entitlement program, cutting it to pay for his signature health care reform law. But they seemed at first reluctant to defend Ryan's plans, with mixed signals on whether Romney would embrace the proposals.
On Tuesday, Ryan didn't bring up Medicare at his two campaign events in Colorado and Nevada, but he was asked about it in a TV interview.
"We are the ones who are not raiding Medicare to pay for 'Obamacare,'" Ryan said Tuesday on Fox News in his first solo interview as a vice presidential candidate. "President Obama is actually damaging Medicare for current seniors. It's irrefutable."
The Obama campaign's attacks on Romney have been tough, and constant. Obama campaign senior adviser David Axeldrod told CNN's Candy Crowley on "State of the Union" on Sunday that Ryan was a "right-wing ideologue."
And on the campaign trail Monday in the battleground state of North Carolina, Vice President Joe Biden talked about Romney and Ryan "gutting Medicare."
With the presumptive GOP nominee in senior-rich Florida on Monday, the Obama campaign touted a Web video that included retirees questioning Ryan's Medicare plan.
"It doesn't make sense to cut Medicare. A voucher plan?" asks one senior in the video.
Ryan's proposals do call for a partial privatization of the government health insurance plan for seniors, but only for those now under age 55 that would go into effect in 2023.
The Romney campaign has fired back, claiming that Obama has cut more than $700 billion from Medicare to pay for his health care law.
"When he ran for office he said he'd protect Medicare, but did you know that he has taken $716 billion out of the Medicare trust fund, he's raided that trust fund, and you know what he did with it? He's used it to pay for Obamacare -- a risky, unproven, federal government takeover of health care," Romney said Tuesday on the campaign trail in Ohio.
And his campaign is going up with what it calls a substantial ad buy Wednesday with a spot that highlights its Medicare pushback.
"You paid in to Medicare for years. Every paycheck. Now, when you need it, Obama has cut $716 billion from Medicare. Why? To pay for Obamacare," says the narrator in the commercial.
The Romney campaign got the $716 billion figure from a July 24 Congressional Budget Office report, which measured the impact of repealing the health care overhaul law, which is known by many as Obamacare. But the report also notes that the projected $716 billion increase in Medicare spending if the measure is repealed does not signal a $716 billion decrease if the measure stays in place -- which is Romney's argument.
The Romney strategy is simple: Accuse the president of robbing a popular program (Medicare) to pay for a program (The Affordable Care Act) in which support is divided. A Romney campaign official says, "The message here is that we are on offense on Medicare. This is a debate we invite."
One thing now appears apparent: The Romney campaign now will have to own the Medicare issue to come out on top in November.
"The Romney-Ryan ticket has now chosen to fight two wars, one on Medicare and one on the economy. They have to tie the first and win the second. If they are still fighting the first one in October, it is going to be hard to put the GOP ticket over the top, said GOP strategist and CNN contributor Alex Castellanos.
"This is going to be a tough year for Grandma. The Democrats are going to say Republicans are pushing her wheelchair over the cliff again and Republicans need to explain, 'Too late, she's already down in the ravine, since Barack Obama has already cut $700 billion from Medicare for current seniors. By November 6, Grandma is going to be black and blue and bruised bottom-to-top," added Castellanos, who was a top media adviser for Romney's 2008 nomination bid.
The Obama campaign sees the choice of Ryan as Romney's running mate as an opening and it's going to continue its attacks on his Medicare proposals, arguing that the plan won't play well in some crucial battleground states in the Midwest.
"They certainly don't see the virtue of turning Medicare into a voucher program. They don't see the virtue of throwing millions of seniors out of nursing homes, and people with disabilities. They don't see the virtue in that, all to pay for tax cuts for the wealthy," Axelrod told CNN Chief National Correspondent John King, Tuesday in Iowa.
But a longtime Republican strategist says the Democratic attack line won't work.
"It seems that the Democrats live in the past like Marshal Henri Philippe Benoni Omer Joseph Pétain, the godfather of the Maginot Line in France in pre-World War II -- use tactics that were successful in past battles. While scaring seniors on Medicare has had some marginal success in some races and some regions, that does not lead to success in every race in every region," said David Carney, a GOP strategist who earlier this cycle served as a senior adviser to Texas Gov. Rick Perry's bid for the Republican presidential nomination.
The clock's ticking in the race to win the battle to define Ryan and his Medicare plan. Stay tuned.