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

With relentless attacks aimed at portraying President Barack 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.'"