But even if Boehner’s decision-making ends up looking like a least-bad approach under the circumstances, he’ll only have won a temporary reprieve. Kurtz Republicanism isn’t likely to go away until somebody else within the party — someone with more movement credibility than the speaker, and more subtlety and vision than Ted Cruz — figures out how to take the energy driving the shutdown and redirect it to more constructive ends.

It’s clear, right now, that the populists can’t be trusted not to drive their party into a ditch. But neither can Republican leaders just declare war on their own base, as some moderates and liberals would have them do.

Instead, Republicans need to seek a kind of integration, which embraces the positive aspects of the new populism — its hostility to K Street and Wall Street, its relative openness to policy innovation, its desire to speak on behalf of Middle America and the middle class — while tempering its Kurtzian streak with prudence, realism, and savoir-faire.

Think of the way that Barack Obama, in his post-2004 ascent, managed to channel the zeal of the antiwar left without being defined by its paranoid excesses, and you can see a recent model for how this kind of integration might work.