It's happened with every other thing he's done.
They don't support it until he does it, and then when he does it, they'll be ready to die on that hill.
He isn't the candidate people who actually hold on to any principles voted for, because he very explicitly has none, and he expects his supporters to not have any either. The only thing that matters is winning.
Everybody ingests at least some of their worldview and opinions from external voices. That's a reality of humans trying to navigate a complicated messy world. But it was really shocking seeing family members hold reasonable view "A", until the local talk radio station sprays out "A bad, B good", and then bam, instant complete retroactive reversal like they never thought "A".
I worked on a farm in middle and high school at the time. Every blue collar dude, farmers, truckers, tradesmen all listened to Rush at lunchtime.
The problem isn't that a political party is acting as hive mind, the problem is that the core pillar of conservatism they practice is 'I will use the law as a weapon against you, but I will not ever be bound by it'.
Which is no way to run a society, any I cannot have any respect for its disciples.