I mean, I've talked to people on the alt-right about how they can be anti-degeneracy but be totally fine with traps/trannies. The general idea is they're only into them now because they hate modern women so much that even men are better by comparison but once most women aren't whores anymore, they won't bother with men who just look like women. According to them, the ultimate fantasy of most traps/trannies is basically being a 50's-style housewife and that just happens to be the ideal male-female relationship to people on the far right. Modern women aren't really interested in that relationship but modern boygirls are so that's why they've become such a popular fetish.
Personally, I don't even believe this line of reasoning. A lot of these people are fucking weaboos and grew up reading hentai and if you read hentai, it's pretty much impossible to avoid traps and all kind of weird fetishes. You'll see people like Nick Fuentes being anti-degeneracy but if you actually hang out in the same places as these people, you'd know how sexually degenerate they are, they don't even try to hide it, especially if you're also a weeb and read hentai. Also, a lot of traps and trannies are just as slutty if not moreso than instagram thots. I'll agree that it's kind of easier to relate and talk to them since they're either dudes or used to be dudes and a lot of them do have a 50's housewife fantasy but it's a fantasy they'd never be able to carry out because they like cock too much.
Bottom line is like you said, as long as you agree with them politically, it doesn't fucking matter what your sexual preferences are.