If some of us seem a little obsessed about the “post-policy” Republican party — the idea that Republicans appear to have lost interest in developing real public policy but have instead settled for mindless slogans and knee-jerk opposition to everything Barack Obama says — it’s because because it seems to be something really new in U.S. politics, with the implications still somewhat uncertain.

One aspect to this that has gone largely unnoticed is that there’s a real risk that even Republican-aligned interest groups will be harmed by the party’s seeming unwillingness or inability to pursue policy compromises or to deliver on anything beyond symbolic victories.

That’s a big part of the excellent New York Times story about how impossible it has been to do routine fixes to the Affordable Care Act. As Jamelle Bouie pointed out, those fixes are routine for major legislation, but impossible now because Republicans simply refuse to do anything that could be seen by Tea Partiers and other potential primary opponents as “accepting Obamacare,” even if it would make it better.

Indeed, some of the complaints about the law come from small businesses and insurance companies — groups normally thought of as at least loosely aligned with the GOP. But the GOP is unwilling to alter the law, even in ways that would make it more friendly to their interests.

One of the core functions of political parties is fighting for the interests of their aligned groups. But Republicans aren’t doing that here; they’re willing, essentially, to sell out very practical gains in order to reap symbolic victories (such as the House’s constant votes against Obamacare).

And it’s not just the Affordable Care Act. The exact same story is happening with sequestration. Republicans are unable to protect the material interests of defense contractors — who want the sequester replaced — because they’re more interested in scoring symbolic points about deficits and taxes, and are insisting on keeping the sequester, rather than compromising with Dems to replace it.

The same may happen with tax reform. It’s pretty clear that Democrats are more than willing to make deals on both corporate and individual tax reform — but if Republicans aren’t able to handle dealmaking, how are they going to look out for their own groups, who will be vying for their priorities as part of reform?

Perhaps the big question is whether at some point some of these groups are going to be so frustrated by the post-policy GOP that they’ll flip sides. That’s probably the biggest danger for Republicans. If they start losing groups which have traditionally supported them, they could really fall into a death spiral in which extremists control a larger and larger portion of the party. And, perhaps even worse, they could become even more unattached from anything beyond the symbolic victories that only a tiny fraction of the electorate care about.

No one knows what it would take to really do that, because we’ve never seen a party like this before. But it sure seems to me like a risk no political party should want to take.