Potentially if he held onto his Senate seat in 2006 after being a candidate for the Republican nomination in 2008, which was widely expected if he had defeated his Democratic opponent, former Secretary of the Navy Jim Webb. Considering he did not pass the above, the former Governor and Senator from Virginia will not make a political comeback in 2012 or 2016. End of story.
Only if he had destroyed Webb. If he had pulled out a narrow victory, after all the problems, he'd have had no shot at the nomination.