Let's cut through the media and punditry rubbish and analyze the Presidential candidates through the prism of a very-close-to-rock-solid, non-partisan political axiom.
Americans do not elect sitting Senators to the White House. Americans know that the Senate is a repository of
megalomaniac mediocrities, worthless scions of
great wealth or
power,
highly polished crooks, but mostly
well-meaning mediocrities with limited worldviews. Not to say that every President we have elected is
not those things, but we have the good sense to lower our chances of being stuck with one by avoiding recruiting straight from the Senate. However...
In modern times there is one exception to this axiom, John F. Kennedy. And it wasn't just an exception, it was a big exception. It proved that Americans were capable of going on a wingding, wot with Kennedy being a stinkin' Irish Catholic and all. Or did it? The election was veeeerrrryyy cloooooose and nearly 22% of the US population was Catholic in 1960. Nonetheless, it is this exception that keeps the likes of McCain, Edwards, Hillary and Barack Obama hopeful.
So, let's take the guy with the least chance of being the next exception (although with the most media attention) first, Barack Obama. He's a lightweight, that's fairly clear. And he's black, which makes him one of a group that constitutes 13% of the US population. So Americans would have to ditch their heretofore reluctance, inability, or whatever to elect a black candidate to a much greater degree than they got over their Catholic heebie-jeebies in 1960 to squeak Kennedy into office...for a guy who only just became a Senator and will have spent over half of his senatorial years campaigning rather than attending to his duties in Congress. Possible? Yes. Likely? No. Obama's least audacious hope is to get on the ticket as VP and play for 2012 and beyond.
Next, Hillary. Obviously she trumps Kennedy in that women are a much greater percentage of the population, but the dynamics of the gender question are not the same as the religious ones that Kennedy had to surmount. It is beyond my pay grade to sort out this psycho-socialogical question. That said, with a major character question - that she is a ruthless, lying, political automaton - hanging over her head, she doesn't have alot to help her overcome the Senate handicap. Her tenure as a denizen of the White House, although not as an elected official, may be enough for some, but here again the role of First Lady has never been seen as one that can impart the skills required of public office and would require a big shift in the mindset of the electorate.
Now on to John McCain. Regardless of his policy views or voting record, John McCain has
already run for President as a sitting Senator and lost to a non-senatorial candidate (the then Governor of Texas who was, at the time, considered a weak candidate). McCain is facing two non-senate candidates this time around and there is nothing to indicate that the electorate has changed its view about him or the electability of Senators. McCain would have been smarter to go back to Arizona and run for Governor, as the presidentially ambitious Jon Corzine did.
Finally, John Edwards is not actually a sitting Senator as Harry Reid helpfully pointed out just last week. Could this help him as he has shed the burden of the Senate? I dunno. Still his only political experience has been as a Senator. History shows us that Americans generally want their Presidents to have done something besides just be a Senator, like run a state or be Vice President. Ditto for Fred Thompson, his blogosphere boomlet notwithstanding.
That leaves Bill Richardson, Rudy Giuliani and Mitt Romney as the only candidates who do not have a severe handicap keeping them from the Oval Office. The smart money would go with one of those three.