Jeff, that's an interesting question.  Either contense will be incredibly intense, but for different reasons.  A McCain versus Clinton contest threatens to draw out the nastier elements of both parties, and consequently lead to each candidate only giving lip-service to issues pertaining to people of color.  Clinton would have to present herself as more hawkish to compete with McCain, who while he's a hawk, he's not one in the mold of Cheney/Rumsfeld, so this could lead to some nasty exchanges that do not benefit either candidate.  This would also be a campaign where both candidates run on their records and not necessarily their visions, and that won't benefit Americans as a whole. 

On the other hand, a McCain versus Obama campaign would be so ideologically heated that it could lead to some serious shifts in American politics-especially if McCain takes Obama's cue and draws Republicans more toward the middle.  Obama will force McCain to articulate a vision for this country, and it would be interesting to see what he comes up with, because it will show voters who he really is and how much he's willing to concede in order to be president.  He can either go far right or drift toward the center and force republicans to do right by this country.  My chief concern is that neither of these two are great debaters-and their mannerisms when on screen could color voters opinions in unflattering ways.

What do other folks think?

Also, what are the possible ramifications of Edward's concession?