One thing we're learning from this election: These really are different parties.

First, look at the Democrats. Listen to the discussion about their strategies. Hillary needs to win more blacks and men. Obama must capture more Hispanics and peel away more white women. Both need to fight for "the youth."

Now look at the Republicans and how we talk about them. Can John McCain win over conservatives? Should he apologize for his support of amnesty or his opposition to tax cuts? Will Mike Huckabee ever make inroads with economic conservatives? Could Mitt Romney have convinced pro-lifers? Were Rudy Giuliani's positions on gays, guns and abortion too liberal?

See what I'm getting at? If substance were water, the Democratic campaign would be a desert. Oh, I know, Hillary's a wonk, and Obama's got enough policy papers to fill the library at Alexandria. So what? Both Obama and Hillary insist there are no major policy differences between them, except for the war and health care.

Their disagreements on these two issues actually demonstrate how little separates them. On Iraq, Obama insists that he was right first. But both of them promise to pull troops out as fast as possible. The only argument between them is how fast that might be. It's hardly a Churchillian conversation.

As for health care, their disagreements are interesting to a few health-care wonks and activists - she wants to mandate universal coverage, he doesn't - but it's all absurdly academic. Anybody who knows anything about how Washington works understands that presidential campaign proposals are, at best, mere discussion documents when it comes time to craft actual legislation. Just as no plan long survives actual combat, no campaign baloney survives the congressional meat grinder unscathed.

But that's it. The rest of their disagreement boils down to who is a more authentic agent of "change." In fairness, there's an interesting debate to be had on that score, as Obama and Hillary's philosophies of government differ dramatically. Obama believes in a transformative politics where lofty - often gassy - rhetoric is not merely a substitute for action, but actually preferable to the nitty-gritty detail work Hillary prefers. Continued...