Obama team fully vetted Biden in 2008 and found no hint of former aide's allegation

David Axelrod, a senior CNN political commentator and host of "The Axe Files," was senior adviser to President Barack Obama and chief strategist for the 2008 and 2012 Obama presidential campaigns. The opinions expressed in this commentary are his. View more opinion articles on CNN.

(CNN) When it became clear that Barack Obama would be the nominee of the Democratic Party in the spring of 2008, he commissioned a team of lawyers to begin an in-depth vetting process of potential candidates for vice president.

Dozens of women and men under consideration were reviewed. Those who rose on the list of contenders were subject to a deep-dive investigation of their strengths, vulnerabilities and, of course, any disqualifying defects.

At the top of the list of those contenders was Senator Joseph R. Biden of Delaware.

The comprehensive vet certainly would have turned up any formal complaints filed against Biden during his 36-year career in the Senate. It did not. The team would have investigated any salacious rumors of the sort that travel far and wide in Washington. There were none.

While I was not on the vetting team, as senior strategist to the campaign, I was briefed on their work and potential problems.