Bush's speechwriter, Michael Gerson, tries to explain the president's foreign policy vision:

Bush's speech appeared to put the United States on a course in which moralism and idealism, rather than realpolitik, form the philosophical foundations of foreign policy. But White House officials said that is a misreading of how Bush operates. "His goals are deeply idealistic," Gerson said. "His methods are deeply realistic. In fact, that was one of the themes of the speech, that this traditional divide between realism and idealism is no longer adequate for the conduct of American foreign policy."

Fair enough. I tend to think that criticizing Bush for being "too idealistic" misses the point, obscuring the man's real flaws. In fact, I'd go even further and say there isn't any serious divide between "realists" and "idealists" among major American thinkers and politicians. (Fringe paleocons like Pat Buchanan don't count, and the Republican isolationists in the House have shown so pliable that they don't really count either.)

Everyone has certain foreign policy ideals, as well as certain senses of limits, and those differ from person to person, but so what. I don't believe, for instance, that Michael Ledeen wants us to focus on ushering revolution into Iran, while I want the U.S. to negotiate with Tehran over nukes, all because Ledeen's an "idealist" and I'm a "realist". Rather, it's because we have very different empirical takes on the situation -- on the viability of revolution, or on the sinister intentions of Iran's mullahs. In certain possible worlds we could reach factual convergence on these issues without altering our theories of foreign policy.

So there's just not a grand distinction to be made. If we really want to categorize Democrats and Republicans, there are other important continuums -- the degree to which a politician/thinker actually wants to emphasize foreign policy (Bush maybe more so, Kerry maybe less so), or the degree to which politicians/thinkers are actually interested in understanding how the world works -- that are better for distinguishing the two parties.