He has been stereotyped as the Obama administration’s gaffe-prone sideshow.

But Vice President Joe Biden also is a veteran debater who was in the U.S. Senate for a quarter century and is perhaps the Democratic White House’s most passionate defender of the working class.

Now, with his debate against Republican vice presidential nominee Paul Ryan coming up on Thursday, Biden is under pressure to help President Barack Obama’s campaign recapture the momentum it enjoyed before Obama was outmaneuvered by Republican rival Mitt Romney last week in the first of their three debates.

“Biden has got something going for him in a debate, which is a sense of humor,” said Alan Schroeder of Northeastern University’s Alan Schroeder, who has written a history of presidential debates.