what do you think they are looking at? and who is Mr. Dodo?

Barack Obama has chosen Delaware Sen. Joe Biden as his vice presidential running mate, a pick designed to shore up the Illinois senator's foreign policy credentials in advance of the November election against John McCain.

Biden's selection was confirmed by a Democratic source after an evening of speculation that centered on the Delaware senator when it was reported that the other top contenders were no longer under consideration. Biden had been considered the frontrunner for the job in recent weeks -- a position confirmed by a last-minute, unscheduled trip last weekend to meet with the president of Georgia.

News of the pick was reported in advance of the Obama campaign's planned Saturday announcement to supporters via email and text message.

Biden was first elected to the Senate in 1972 at the age of 29. A month after his election, his wife and daughter were killed in a car accident. Biden has not been seriously challenged since that first election -- a reflection of both the Democratic roots of the state and Biden's skillfulness as a politician.

Long rumored as a candidate for national office, Biden launched a presidential bid in 1987 that was gaining traction until a video was leaked to the press that showed striking similarities between a speech by Biden and an address by British Labour Party politician Neil Kinnock. Biden sought to beat back the controversy but subsequent allegations about plagiarism and resume inflation in law school forced him from the contest.

Biden was subsequently stricken in early 1988 by a brain aneurysm from which he recovered fully. Once his health improved, Biden threw himself back into the day to day working of the Senate where he chaired the high profile Judiciary Committee from 1987 until 1995. In that role, he chaired the controversial Supreme Court confirmation hearings of Robert Bork and Clarence Thomas. Biden has also served several stints as the chairman of the Senate Foreign Relations Committee, a perch from which he has emerged as one of the leading voices in the Democratic Party on foreign policy matters.

Two decades after his first bid for president, Biden launched a second candidacy in 2007. He was never considered anything more than a longshot due to the presence of both Obama and Hillary Rodham Clinton in the contest but acquitted himself well in the eyes of the Democratic establishment. Biden proved that the charisma that had recommended him as a rising star in the 1980s was still very much part of his political portfolio; he also excelled in the myriad debates held among the Democratic aspirants during the primary season.

For Obama, the Biden pick is a sign that he and his campaign believe that foreign policy matters will be front and center in the fall election. Biden brings the Democratic ticket immediate gravitas on issues ranging from the war in Iraq to the ongoing conflict between Russia and Georgia.

McCain has made no secret that he believes Obama's experience in public life ill suits him to handle the complex world situation into which the next president will immediately step. Biden, a serious politician with a far deeper resume than Obama, will complicate -- if not entirely blunt -- Republican attacks on the Illinois senator's readiness for office.

We'll have far more about the pick both on The Fix and the washingtonpost.com site more generally throughout the day. In the meantime, make sure to check out the case for and case against Biden as vice president we made in this space. They should provide a blueprint for how Democrats and Republicans will try to define the Delaware senator in the coming weeks and months.