He’s endorsing Hillary only because he thinks Donald Trump will destroy the Republican Party for years to come (and he’s right about that), but Bret Stephens is the latest hardcore Hillary hater to bite the bullet.

The best hope for what’s left of a serious conservative movement in America is the election in November of a Democratic president, held in check by a Republican Congress. Conservatives can survive liberal administrations, especially those whose predictable failures lead to healthy restorations—think Carter, then Reagan. What isn’t survivable is a Republican president who is part Know Nothing, part Smoot-Hawley and part John Birch. The stain of a Trump administration would cripple the conservative cause for a generation.

This is the reality that wavering Republicans need to understand before casting their lot with a presumptive nominee they abhor only slightly less than his likely opponent. If the next presidency is going to be a disaster, why should the GOP want to own it?

Stephens is concerned about the “blood and soil nationalists” Trump has legitimized, but he still doesn’t seem to realize that this racist, fascist element of the right wing base has been courted and pandered to by the GOP for years. And now they want to move in, hang their white power posters on the walls, and take over. Good luck throwing them out.

But Trumpism isn’t just a triumph of marketing or the excrescence of a personality cult. It is a regression to the conservatism of blood and soil, of ethnic polarization and bullying nationalism. Modern conservatives sought to bury this rubbish with a politics that strikes a balance between respect for tradition and faith in the dynamic and culture-shifting possibilities of open markets. When that balance collapses—under a Republican president, no less—it may never again be restored, at least in our lifetimes.