CHARLOTTE, N.C. – Republicans have a new rhetorical punching bag: Vice President Joe Biden.

With relentless attacks aimed at portraying President Obama’s running mate as a governing liability, Republicans hope to raise the stature of GOP vice presidential candidate Paul Ryan, who will debate Biden next month, and score points in closely contested states such as Ohio, Florida and New Hampshire.

“Paul’s a close friend, a great family man, and he’s got a reformer’s heart,” Ohio Sen. Rob Portman said at last week’s Republican convention in Tampa, Fla. “Contrast this to Joe Biden. Vice President Biden has told people out of work to ‘just hang in there’ — so much for ‘hope and change.’

As Democrats prepare for their convention in Charlotte, N.C., the GOP is casting the 69-year-old former Delaware senator as a gaffe-prone crazy uncle who’s hung around the political scene too long. The strategy tries to undermine the Obama campaign’s chief surrogate and liaison to white, working-class voters and seniors, influential groups courted aggressively by both parties. At the same time, Republicans hope that sullying Biden’s image will help confirm Ryan, the 42-year-old Wisconsin congressman, as a deep thinker destined to take on many of the nation’s most pressing challenges.

In an opinion piece published this past week by the Milwaukee Journal Sentinel, Wisconsin Sen. Ron Johnson noted that Biden had said the economy felt like “a depression” and he accused the vice president of straying from “the Obama campaign talking points.”

At the GOP convention, Ohio Gov. John Kasich recalled Biden telling him he was a “good golfer. And I played golf with Joe Biden, and I can tell you that is not true, as well as all of the other things that he says.”

Actor Clint Eastwood’s convention monologue, beside an empty chair, included a swipe at Biden.

“You’re crazy, you’re absolutely crazy. You’re getting as bad as Biden,” Eastwood cracked in his made-up conversation with Obama. “Of course we all know Biden is the intellect of the Democratic Party. Kind of a grin with a body behind it.” 

“It’s an attempt to undermine what they believe is a potent political weapon in the Obama campaign’s arsenal,” said Democratic strategist Mike Feldman, a former aide to Vice President Al Gore. “If they were ignoring him, that would tell you that they’re not that concerned.”