Who is Joe Biden?

Pros:

1. Biden's experience with international affairs is heralded with his title, chairman of the Senate Foreign Relations Committee
2. Biden knows how to play the important vice presidential role of attack dog, as he did during the debate over Supreme Court nominees Clarence Thomas and Robert Bork.
   
3. He could help shore up a couple of important constituencies for Obama: white Catholics and Latinos. Obama struggled with both groups in the Democratic primary. Biden's working-class Catholic background could help with that set of voters, and both his faith and his support for more liberal immigration laws might appeal to Latinos.
4. Biden is more moderate than most people think. His high-profile role in judicial nominations gives him a liberal image, but he is a centrist on many issues both foreign and domestic.
   

And a few cons:

1. Biden could say anything at any time -- ranging from the incisive to the insightful to the funny to the offensive to the weird. Reporters love it; presidential campaign aides not so much.
2. The Experience Trap: Biden's long foreign policy resume and facility with international affairs could draw even more attention to the thinner record of Obama, who is a junior member of Biden's committee. If Obama is seen as the least ready of the four presidential and vice presidential nominees between the two parties, it could be harmful to him. Then again, picking a running mate with little or no foreign policy or national security experience might be worse.
3. It is also a pro, but Biden is more moderate than most people think. He has parted with liberal Democratic orthodoxy on any number of issues, including -- but not limited to -- his support for a ban on late-term (or partial birth) abortions, free trade, tax cuts for married couples, and -- way back when -- legislation intended to prevent the busing of students to achieve desegregation of schools.

In Biden, Democratic presidential candidate Barack Obama has chosen a running mate with strengths in areas where Obama is perceived to have deficits. Biden's experience -- six terms in the Senate -- and his deep knowledge of foreign policy and the ways of Washington head the list. Moreover, as an Irish-Catholic, lunch-bucket Democrat, Biden may also help Obama appeal to a bloc of white, blue-collar voters who resisted him during the nomination fight.

If Obama intends to ride in and clean up the political culture of Washington, he's chosen a gray eminence, instead of a fresh face, to ride shotgun.

Compared to Obama, who is often characterized as cool and cerebral, Biden is direct and earthy. In May, when President Bush, addressing the Israeli Knesset, suggested Obama was willing to appease terrorists, Biden's offered a raw retort. "This is bull----. This is malarkey," he said.

Ironically, Biden, who has a reputation as a motormouth, kept a lid on the biggest secret in American politics -- his selection as vice presidential candidate.

Biden, the chairman of the Senate Foreign Relations Committee, has been a frequent critic of the Bush administration's handling of the Iraq war. He voted for the war resolution in 2002 but later said it was a mistake based on administration intelligence reports about weapons of mass destruction that proved to be false.

Now 65, Joseph Robinette Biden Jr., has spent more than half his life in the Senate, since his election at the age of 29 (he reached the constitutional threshold age of 30 between his election and swearing in). From a young age, Biden considered himself presidential material. His first run ended disastrously when he dropped out in the fall of 1987 after his candidacy was engulfed by charges of plagiarism and embellishing his academic record. He said later he was not mature enough to be president then.