Some intellectual conservatives believe that the Tea Party populism will be domesticated by governing. Says one: “The movement doesn’t last through 2012 in anything like its current form. It will carry a Republican House and less Democratic Senate, but its energy will inevitably dissipate as national politics becomes more complicated with divided government and the economy improves some. That’s why I think the policy wonks are important — people proposing real ideas, how smaller government should mean a more robust civil society, while making sure there is a safety net for the poor. The new House might listen to these ideas more than the protesters themselves.”

But it is also possible that the Tea Party will define the hated “establishment” not just as moderate Republicans such as Mike Castle of Delaware but also as moderate conservatives of every stripe. Many Tea Party activists espouse a “constitutionalism” that amounts to an extreme libertarianism. Their goal is not just deficit reduction but the dismantling of the modern state. And they may prove harder to tame than some imagine.

A Republican Party propelled by Tea Party enthusiasm is headed toward victory. A Republican Party dominated by Tea Party ideology would be pure, disturbing — and small.