My Campaign Stops column this week tries to explain how the current intersection of national security and immigration in the headlines (including in today’s Times) has left the Republican establishment particularly defenseless against Donald Trump’s demagoguery, because the combination of Bush-era foreign policy failures and the party elite’s consistent dissembling on immigration policy (against amnesty in even-numbered years, otherwise for it) has eroded voter trust to a point where a normal partisan pitch on this issues falls on quite a few deaf ears.

But it should be stressed that it doesn’t fall on deaf ears everywhere. There are many Republican voters who think the Iraq invasion was a necessary decision and that the only grave failure in the Middle East was Barack Obama’s squandering of the surge’s gains; there are many Republican voters who are either in tune with the party’s leadership on immigration or else haven’t ever particularly focused on the issue; there are many Republicans who simply aren’t going to vote for Trump even if they agree with some of his blasts against the establishment.

And those Republicans remain, most likely, a majority within the party. His post-Paris, post-San Bernardino bump has left Trump with about 30 percent of the vote in national polls, but 30 percent is a long way from 50 percent, and his basic coalition is still probably the same distinctive mix it’s been all along: He seems to be combining certain very right-wing voters (the kind who listen to Rush and watch Hannity and read Breitbart, his chief boosters in the conservative movement) with a working-class, disaffected, radical-middle constituency that usually identifies itself as “moderate” or “liberal” in typologies of Republican voters and holds genuinely middle-of-the-road views on economics.