Opinions of Biden low before VP debate

Vice President Joe Biden speaks during a campaign event at the Century Village Clubhouse in Boca Raton, Fla., Friday, Sept. 28, 2012.
AP Photo/Terry Renna

When he takes the stage in the one and only vice presidential debate on Thursday, Vice President Joe Biden will have to overcome low public opinion ratings and low expectations.

Just 39 percent of voters have a positive view of Biden, according to a new Pew Research Center poll, while 51 percent have a negative view. By comparison, 44 percent have a favorable view of Republican vice presidential candidate Paul Ryan, while 40 percent have a negative view. The poll was conducted Oct. 4-7.

Similarly, Pew found last month that when asked for one word to describe Biden, nearly four in 10 gave negative responses like "idiot."

The vice president's favorability rating is lower than it was four years ago, ahead of his debate with then-VP candidate Sarah Palin. In late September 2008, 53 percent of voters had a positive view of Biden. Palin's favorability rating at the time, which stood at 51 percent, was higher than Ryan's now.

In a separate poll, Pew found that more voters (40 percent) expect Ryan to do a better job in Thursday's debate than Biden (34 percent).

The low expectations may serve Biden well -- candidates typically lower expectations ahead of a debate so their performances receive gentler reviews. Ahead of the first presidential debate last week, voters were more likely to say that President Obama would win, but after the debate, more said that Mitt Romney won.

It's up to Ryan this week to keep up the GOP ticket's momentum, but he's cautioned that he expects Biden to come at him "like a cannonball."