True, the make-up and priorities of both Republicans and Democrats have changed a few times over the years.

I would say that in this case, it's a party aligning to an individual far more than it has ever been in the past. Racist Southern Democrats didn't become Republicans because they were enamored with a Republican leader, they changed parties because they found themselves misaligned with the Democratic Party's pivot to civil rights.

I wholeheartedly agree that a parliamentary system would serve the US better.