I should clarify what I think, because this is important stuff.
I do think that Republicans have become "post-policy" in the sense that they have largely given up on attempting to construct real public policy solutions. That fits with, for example, the record of the GOP House in rarely actually passing bills. I haven't used the "nihilist" part of that...I don't disagree with Kilgore that hard-core conservatives do have preferences, or at least impulses, on some policy areas.
Sometimes that's real: abortion, for example, is something that a lot of Republicans really do care about. Lower taxes for wealthy people, too, is a clear line that they care about.
But on lots of other issue areas, it's a lot harder to tell. Lower taxes overall? Conservatives absolutely did not accept Obama-era tax reductions. Cuts to Medicare? We know all about the back-and-forth they've had on ACA Medicare cuts. "Obamacare" itself? Well, you know my position on that: they sure do hate Obamacare, but they're not particularly against the Affordable Care Act.
But basically, for most movement conservatives on most policy questions, the concern is far more symbolic than it is substantive.
Now, that's clearly not true for all conservatives and for all Republican-aligned groups on all issues. Neocons really do care about
But stuff like the Obamacare crusade sure seem far more symbolic than substantive to me. So does climate denialism, and so does much of the deficit, and even size of government, rhetoric. To me, the overall evidence, found in sudden swings in party positions on various issues over the years, is overwhelming.