I would not have thought Sen. Joe Biden would even get on the short list. But now I can only assume he will get the VP nod tomorrow.

It would seem that Gov. Tim Kaine, Sen. Evan Bayh and Biden have been floated as trial balloons, with Gov. Kathleen Sebelius kept on the backburner as a possible "surprise" pick.

Kaine was greeted with a yawn. Bayh received some fierce pushback from the base.

But the pundit class has responded warmly to the media accessible Biden.

And the base did not push back hard on Biden.

Apparently, whatever policy disagreements people have with Biden (Iraq vote, bankruptcy bill), there remains recognition that Biden can play a high-minded attack dog, with enough stature to get in McCain's face and rebut neocon lies.

(One of the best lines of the campaign was Biden's definitive smackdown of Rudy Giuliani: "There's only three things he mentions in a sentence: a noun, and a verb and 9/11.")

Following a successful trial balloon, and with no deep support for an alternative pick, it would seem odd at this juncture if Obama went a different route.

I did not expect such an outcome because Biden is one of the worst offenders of freelance messaging, and I would think Obama would want confidence of message discipline.

But Biden has functioned well as a surrogate since Obama wrapped up the nomination, so perhaps Obama has found that confidence.

I've talked to some liberals who can't see how Obama can pick the guy who called him "the first mainstream African-American who is articulate and bright and clean and a nice-looking guy."

I actually consider that a plus.

Where Obama could stand to make inroads is with white middle-age and senior voters -- folks who grew up with different racial sensibilities, and folks who get ruffled when impolitic remarks get called out as racist.

For Obama and Biden to campaign side-by-side renews a key element of Obama's all-too-quickly forgotten race relations speech:

...to wish away the resentments of white Americans, to label them as misguided or even racist, without recognizing they are grounded in legitimate concerns - this too widens the racial divide, and blocks the path to understanding.

The McCain campaign was trying to maintain this racial divide, by accusing Obama of playing the "race card" -- a charge which sounds ridiculous to many, but not necessarily to voters in Biden's demographic.

Biden can help prevent that strategy from working -- not by pandering to bigotry, but showing by example that we share common ground and goals.

But we'll find out soon enough, perhaps tomorrow, if it is Biden.

And if it is, we'll find out soon enough if he delivers the right hook that allows Obama to stay on the high road.