Regarding the emergence of a genuine third party candidate (a serious idea), I think Hillary Clinton would love nothing more, because it would make it easier for her to paint herself as the "real centrist" that confused American voters have been waiting for.

Glenn Reynolds discusses the conventional wisdom problem:

The conventional wisdom, of course, is that a third-party candidate can't win. That's been the lesson of recent history. But had Ross Perot been a bit less kooky, he might have pulled off a victory in 1992. And technology for mobilizing disaffected voters has advanced beyond the state of the art then, which consisted of toll-free telephone numbers. Thanks to the Internet and alternative media, reaching disaffected voters and rallying them behind a candidate is likely to be much, much easier than it was back in the 20th Century. (We saw an early illustration of this phenomenon with the insurgent campaign of Howard Dean, who, if he had been a bit less kooky, might have pulled off a victory in the Democratic primaries.)

I'm afraid that, like it or not, the flash appearance of a third party candidate from the ranks of the techno-savvy would create an opportunity for a "mainstream centrist" like Hillary to contrast her own demonstrated populism with this "new elite." The many voters who don't use the Internet as a news source would probably love being reassured.

If John McCain had any sense, he'd read Mickey Kaus's analyses carefully, because McCain is one of the few Republican presidential aspirants seen as an outsider. This means that he could possibly have his cake and eat it too. If he got solidly behind the idea of building a fence (a now-centrist position that a large popular majority supports), the numbers are there for him to run as an outsider (attacking both parties for border incompetence -- possibly even threatening to run as a third party candidate), only to eventually "seize" the Republican nomination via an "insurgency" movement. This would pre-empt Hillary (an immigration flip-flopper) on the much neglected but highly popular fence issue. As a Republican and an Arizonan, McCain can position himself as innately more credible on border issues than an Democrat "from" New York -- provided he has the sense to lay claim to the issue.

(But it's not for me to decide who has sense and who doesn't.)

MORE: Via Glenn Reynolds, Tim Blair (and, of course, Kos himself), it has now become clear that Kos has weighed in against Hillary Clinton. I agree with Tim Blair that this clinches it for Hillary. I also think such "elitist" opposition assists Hillary's carefully crafted populist image. However, there's a split on the left side of the blogosphere, and I predict the dissenters will swallow their (gulp) pride, and eventually get behind "centrist" Hillary.

MORE: According to Drudge, Rupert Murdoch is hosting a fund-raiser for Hillary Clinton:

Rupert Murdoch has agreed to host a political fundraiser for Hillary Clinton this summer!

Murdoch's surprise decision to raise money for Clinton in July, on behalf of NEWS CORP., parent company of FOXNEWS and the NEW YORK POST, underlines a dramatic turn of relations between Murdoch and Clinton, who in 1998 coined the phrase “vast rightwing conspiracy” to denounce critics of her husband.

I keep saying the right wing wants Hillary to be president, but no one seems to believe me.

With Hillary as president, the right wing conspiracy will be profitable once again.