I don't want to get into a protracted argument, but the presidential primary system for POTUS is different than primaries in general. First to the pole while on a country wide tour collecting votes has some real flaws. But, it does weed out extremists. This is just true.

If you want to say that party insiders determine the narrative particularly for POTUS, that's fine, but it's the position of the extremists that this happens and they are excluded because of it.

I have a hard time seeing someone like McKee as voted in by ideologues or extremists. Unless there is such a thing as extremely meh.