A little while back, Greg Mankiw praised Peggy Noonan for "summarizing a key difference between the political parties." As Noonan puts it:
Neither party ever gets it quite right, the balance between the taxed and the needy, the suffering of one sort and the suffering of another. You might say that in this both parties are equally cold and equally warm, only to two different classes of citizens.
In my view, though, Noonan is only successful at summarizing popular misconceptions about the differences between the political parties.
The first big misconception is the parties' key differences are substantive. They aren't. Reps don't want to get rid of the welfare state. Almost all Reps support spending a big chunk of GDP on America's poor and old. And Dems don't want anything like socialism. Almost all Dems want America to remain a country where markets are the default and people can get rich if they play their cards right.
So what is the "key difference" between the parties? Rhetoric. When Republicans advocate a small contraction of the welfare state, Democrats claim that Republicans totally oppose the welfare state. And many Republicans oblige them by standing up for "liberty" and "responsibility." Similarly, when Democrats advocate a small expansion in the welfare state, Republican claim that Democrats oppose free markets. And many Democrats oblige them by saying things like "markets only benefit the rich."
This rhetorical illusion is so powerful that when a Democrat like Clinton adopts many pro-market reforms, Republicans still hate him as a 60s radical. And when Bush II sharply expands the welfare state, Democrats still hate him as a billionaire's lackey.
The second big misconception is that the parties' rhetoric makes sense on its own terms. It doesn't. If Dems really cared about poor human beings, they would quit worrying about the American old, most of whom aren't poor. In fact, they would quit worrying about the American "poor," because by world standards, they're doing fine. Instead, Dems would concentrate all their efforts on helping absolutely poor foreigners, presumably through a mixture of permitting massive immigration, and redirecting welfare to the world's bottom billions.
Similarly, if Reps really cared about "over-burdened" tax-payers, they would try to diminish the burden in the only sustainable way: Big cuts in spending. They would be crusading against the popular programs like Social Security and Medicare that absorb most of our tax dollars. While they're at it, they might want to do a little cost/benefit analysis of the War on Terror.
I understand, of course, that if either party tried to bring its substance in sync with its rhetoric, it would go down in flames. As the Median Voter Theorem explains, parties that refuse to move to the political center don't survive. What the MVT fails to predict, though, is the disconnect between partisan substance and partisan rhetoric. You'd think that rhetoric would be every bit as moderate as action - but it's not.
What's going on? My best guess is that the rhetoric is the bone each party throws its idealists - "If you vote for us, we'll pretend to want radical change." But perhaps even moderates enjoy the illusion of a partisan rift - or at least the illusion that they're on the side of principled moderation against rabid extremism.