Yes, statistically, of course we're past due for a female president. That doesn't mean it has to be her, just so we can begin to even things out. Statistically, we're also past due for a person of color to be president as well. Population percentages do not change the realities of the situation, and we should not give someone preferential treatment, carte blanche access to the highest office in the land, just because they happen to be a minority.
We will have a female president eventually, and she will likely be the Ginger Rogers of politics: doing everything Fred Astaire did backwards and in heels, as the saying goes. In other words, she will simply be the superior candidate, and she will win. To be blunt, Hillary is not particularly exceptional or superior. Her politics resemble those of Joseph Lieberman on several fronts, and the farthest he ever got was as veep candidate on the Gore ticket. Put flatly, she's getting more attention than she'd otherwise get because she's female. She's the green kangaroo in a lineup of Democratic candidates. She stands out due to a physical difference, as Obama does, to a slightly lesser degree. (Side note: out of all the candidates on either side, he gets my vote for Most Impeccably Dressed. I've never seen a picture of him where his suit wasn't perfectly tailored.)
If the Democrats do not want to see four to eight more years of Republican rule, I am convinced that the nominee must be someone other than her.
Incidentally, the shoe fits on the other foot as well: if the Republicans want to win, they need to make Giuliani the nominee. Anyone else is too far to the right, and will likely create a backlash from anti-Bush sentiment.
Frankly, I'll be curious to see how spoiler voters play this out: will right-wingers cross party lines to vote for Clinton in a primary, based on their belief that she cannot win nationally? Will left-wingers cross over to vote for Giuliani out of fear based on the way the country went for Bush last election -- that at least if they're outnumbered, they'll get someone less distasteful than Huckabee or Romney? Will they hold their noses and vote for Huckabee with the thought that he's too alienating to win nationally? It could be interesting.
Both camps need to go moderate with the nominee, and I think it's likely to be a close race. A polarizing candidate cannot win against a moderate candidate this time, I do not think, so each party, to be sensible, must pit moderate against moderate. The hard left and right will just have to cope with this.
It has been said that many people vote with their hearts in the primaries and with their heads in the general election. In this case, I believe it is best to vote with one's brain both times, lest we risk another situation of radical extremes that perpetuates the partisan divide.