When Rep. Paul Ryan was introduced this weekend in Norfolk as Mitt Romney's vice presidential running mate, Republican Senate candidate George Allen was standing nearby, as the first candidate in the country to bask in the glow of the new Republican ticket -- and potentially the first to feel the fallout of Romney's choice of Ryan.

By Tuesday, Allen's Democratic rival, Tim Kaine, was attacking Allen as a supporter of Ryan's plan to dramatically alter the popular Medicare program and accused Allen of wanting to privatize Social Security, both issues that could particularly hurt Allen among senior voters.

It was a turn of fortune for Kaine, who for more than a year has endured attacks from Allen and other Republicans who use Kaine's friendship with President Obama to link the former governor to Obama policies, like his health care reforms, that are unpopular with Virginia voters.

If Allen can tie Kaine to the problems in Washington through his association with Obama, Kaine is now trying to do the same to Allen using Ryan.

"Paul Ryan on the national ticket as a running mate and appearing on the ballot with George Allen is going to amplify a lot of the contrasts we've been making throughout this campaign," said Kaine senior adviser Mo Elleithee. "I'd like to be able to send [Romney] a thank-you note for picking Paul Ryan and allowing us to make this contrast more sharply."

Kaine's campaign is hoping to force Allen into defending Ryan's plan to turn Medicare into a voucherlike program that would help beneficiaries buy private health insurance. Allen has not endorsed the specifics of Ryan's budget blueprint, Path to Prosperity, but has commended Ryan for jump-starting the debate.

Kaine is hitting Allen for supporting a Bush administration proposal for the partial privatization of Social Security when he was in the U.S. Senate between 2001 and 2007.

"[Allen] has spent a lot of time trying to avoid talking about both these issues," Elleithee said. "The selection of Paul Ryan is going to make it very difficult" to continue avoiding them.

Allen responded Tuesday by attacking Kaine for supporting Obama's health care overhaul, which cuts Medicare growth by $700 billion over the next decade.

"Tim Kaine is the only candidate in this race who supports a plan that could bankrupt Medicare by raiding $700 billion for the health care tax law," said Allen spokeswoman Emily Davis. "Tim Kaine's prescription for seniors is higher costs, fewer choices, and the government between patients and their doctors."

Kaine and Allen are deadlocked in a race to replace retiring Sen. Jim Webb, D-Va.