Edwards Performs Best In General Election Match-ups

We all know the questionable validity of national polls this early but I thought this one was interesting. The new Rasmussen poll shows Sen. John Edwards beating every single top tier Republican candidate in general election match-ups.

Edwards 47% Giuliani 45%
Edwards 48% McCain 41%
Edwards 55% Romney 29%
Edwards 53% Thompson 32%

By contrast, the poll finds that Giuliani would cream Obama 51% - 39%, and Clinton would lose to both Giuliani and McCain by 3 points and 6 points respectively.

Now look at the result when you average out the Dems' support against all the Republican candidates:

[F]ar and away the best general election performance was earned by Edwards. He topped the four Republicans by an average of 51% to 37%.

As opposed to:

Obama led the Republican hopefuls by a single percentage point, 45% to 44%. Clinton attracted 45% of the vote on average and trailed the Republicans by a single percentage point.

So what's behind Edwards's general election match-up strength when he's consistently polling in third place for the Democratic nomination? Is it that swing voters are just more comfortable voting for a white southern man if given the choice? Is it that he was on the 04 ticket, so unlike the other candidates people are used to seeing his name in the context of a presidential campaign (i.e on bumper stickers...)? Perhaps a combination of the two. Whichever it is, it would certainly seem to signal the viability of an Edwards candidacy despite the media's claims that he's running too far to the left of the American people. But it also speaks to Clinton's high negatives (47% of voters said they'd vote against her if she won the nomination) and Obama's lack of a clear national reputation as a leader.