From Ronald Brownstein and David Wasserman's cover story on smart voters tending Democratic:

Republicans face an array of challenges with these voters. The GOP's anti-tax arguments that still stir business owners and executives appear to resonate less strongly with these professionals, even though Clinton raised taxes on many of them and they are again in the crosshairs of Obama's pledge to repeal Bush's tax cuts for the very wealthy.

"Some people, as they get more affluent, are OK with spending more money if the services are in line," says DuHaime, now a managing director at Mercury Public Affairs. Other analysts say that the combination of Clinton's fiscal rectitude and the huge deficits racked up on George W. Bush's watch erased any fiscal-responsibility advantage that Republicans once enjoyed with these voters.

The larger current is that many educated voters have recoiled from the same conservative cultural and foreign-policy positions that have attracted many blue-collar voters to the GOP. The backlash against the Iraq war, for instance, has hurt the GOP among college-educated voters, who generally respond more favorably than other voters to a foreign policy that emphasizes diplomacy.