the premise seems that both parties are the same because the majority will support the party.

No, that's not the premise we've been talking about.

It was asserted upthread that Republicans are delusional or misinformed or lying to themselves, in a way that Democrats are not, because they're supporting a President that's doing a lot of things that they do or should hate. I just don't think that's true. I think Trump still has support among his base not because they are delusional or lying to themselves, but because they have very different values and priorities than most of the folks on this board. They care deeply about social conservative issues and the border and stopping a lot of progressive priorities and a host of other things, and they almost certainly couldn't care less about the East Wing or the Kennedy Center or whether Trump's extended family is out there cutting real estate or crypto deals.

It's not an assertion that the parties are the same in all respects. The GOP has very different values than the Democratic party (and obviously vice-versa). Rather, it's just pushing back on the idea that GOP voters are misguided delusional fools who are lying to themselves about Trump.