What's behind these sharp divisions? You could sum it up by saying that Jacksonians are fighters and academics (and public employees) are not. Jacksonians fought fierce battles against Indians as they moved southwest; they have always made up a disproportionate share of the American military (and were on both sides in the Civil War).

As historian David Hackett Fischer writes in "Albion's Seed," they believe in natural liberty -- I'll leave you alone if you'll leave me alone, but if you attack my family or my country, I'll kill you. Academics are, to say the least, lightly represented in the American military, and in economic terms they tend to compete with the military for public dollars. They seek honor for the work of peace as fiercely as Jacksonians seek honor for the feats of war.

Barack Obama notes again and again on the campaign trail that he spoke out against going to war in 2002 and calls for withdrawal from Iraq, though on terms that he leaves hazy and vague. This suits academics -- and many journalists with similar mindsets -- just fine. It's in line with their portrayal of our soldiers as victims, not heroes, and their portrayal as heroes the academics (Obama used to teach at the University of Chicago Law School) who spoke out against the war.

Hillary Clinton from the beginning of the year has portrayed herself consistently as a fighter, on the campaign trail if not in Iraq, and has done best when she kept fighting while her campaign seemed on the brink of collapse. Her story about being under fire in Bosnia turned out to be untrue, but it is true that we have seen her rebound from adversity multiple times over the last 15 years.

Polling suggests that the Democratic nominee may not be able to count on the losing candidate's tribes in November. Academics and young people and blacks may not turn out in extraordinary numbers for Clinton, as they have for Obama, and the upscale may prefer McCain to a tax increase.

Similarly, Jacksonians, the elderly, the downscale and Latinos may prefer the very Jacksonian McCain to Obama. All of which should worry the super-delegates who must determine who wins the Democrats' tribal war.