Vice President Biden looks out the car window during a planning meeting with staff, Vice President Joe Biden is driven back to the White House after speaking to lawmakers, woman against violence advocates, and constituents concerning reducing domestic violence homicides in Rockville, Maryland, on Wednesday, March 13, 2013. (Photo by Melina Mara/The Washington Post) ( Melina Mara/The Washington Post)

President Obama is well known for using teleprompters: His reliance on them for speeches during the 2012 campaign became a regular talking point for his Republican rivals, several of whom vowed to jettison the device  to convince voters of their alleged authenticity.

Vice President Biden's political persona, by contrast, is defined by his penchant for making off-the-cuff remarks. Sometimes they're short but potent — like when he said last year he was "absolutely comfortable" with gay couples having the same rights as straight ones — while other times they are downright meandering, like when he brought down the house at the funeral for the late Sen. Frank Lautenberg (D-N.J.).

During that speech, Biden complained that Lautenberg got more love from Amtrak officials than he did, and that Lautenberg beat him in the obnoxious grandfather category. "I saved Amtrak three times before he was elected. I don’t know how the hell this happened," Biden said at one point. "That’s mostly true.”

By contrast, Obama's most memorable recent off-the-cuff moment came during his bus tour last month when he said, "This is probably controversial to say, but what the heck? I’m in my second term, so I can say it. I believe, for example, that law schools would probably be wise to think about being two years instead of three years.”

The vice president's love of riffing was on full display Thursday night at an event commemorating the 19th anniversary of the Violence Against Women Act, where he boasted, "I understand the Senate better than any man or woman who's ever served in there," and faulted "this sort of Neanderthal crowd" in the House for holding up the bill's reauthorization this year.

He even alluded to the fact that he "went off script" in declaring his support for same-sex marriage, which prompted a few days of extreme discomfort for the administration until Obama also came out in favor of gay marriage. "I make no apologies on the issue of marriage," Biden said Thursday night.

While Biden's comment on same-sex marriage didn't end up hurting the reelection campaign, other comments last year were more cringe-worthy, like when he told a Danville, Va., crowd that included many African Americans that Mitt Romney and his allies would "unchain Wall Street" but in doing so: “They gonna put y’all back in chains."

But for the most part, Biden serves a powerful role as someone who can mobilize the base — like when he told an audience at a fundraiser for now-Sen. Ed Markey (D-Mass.) that they needed to worry about blacks and Latinos not turning out in a special election — and serve as a truth teller, both about himself and politicians around him.

Vice President Joe Biden claimed he knows more about the Senate than any man or woman who's ever served there. Here's a chronological look at four others who might give Joe a run for his money. (The Washington Post)

And while many presidents are restrained in public, it is a reminder of just how much Obama watches his words in the current polarized political climate.

Biden's aides are hoping this frankness will help him if he decides to run for president in 2016. While he would face a challenge getting the nomination, one thing is sure: Reporters covering his campaign would love every minute of the off-the-cuff Biden, a sort of throwback politician willing to speak his mind almost all the time. So would some of his fans, who yelled "keep going" last night when Biden apologized for talking for nearly half an hour.