Obama Makes Up His Mind on Running Mate

Aug. 19, 2008— -- Sen. Barack Obama has decided on who will be his running mate, but as of late Monday night he had yet to notify the candidate, ABC News has learned.

Obama is expected to make his decision public by the end of this week, ahead of next Monday's Democratic National Convention.

He and his staff have made the veepstakes Washington's hottest guessing game, and to avoid having the name leak out, fewer than a half-dozen of Obama's aides know whom he has selected.

Speculation has centered around three candidates: Delaware Sen. Joe Biden, Indiana Sen. Evan Bayh and Virginia Gov. Tim Kaine.

When Obama gives the signal that he is ready to make the announcement, it won't be done with a noisy news conference. Instead, a plan is in place to e-mail his choice to supporters and the media simultaneously. A campaign tour through swing states with the nominee will soon follow.

The best-kept secret has spawned almost daily rumors and theories about Obama's choice and his thinking process, often amusing Obama when he hears them.

Although a dark-horse candidate is always possible, aides suggest that Obama has pared his short list down to Biden, Bayh and Kaine. Each comes with advantages and disadvantages for the Democratic nominee.

Biden, chairman of the Senate Foreign Relations Committee, comes with pages of experience with foreign affairs, and he just returned from personally assessing the showdown between Russia and Georgia. He would give an Obama ticket heft on foreign policy, something that Obama's resume lacks. He is also a Catholic and has appeal to white, working-class voters.

But having been first elected to the Senate in 1972, Biden also could be tagged as a Washington insider, and is hardly a fresh face , which would clash with the Obama theme of championing change. And while his garrulous nature could be an asset come October, he can be gaffe-prone, as when he infamously referred to Obama last year as "articulate" and "clean."

Bayh, a popular former governor of Indiana, a state Obama desperately wants to win, also bolsters an Obama ticket on national security issues. He is relatively young and telegenic and, as a supporter of Sen. Hillary Clinton during the primaries, could possibly help bridge the gap with Clinton supporters.