“Do GOP “moderates” have any reliable base?”
They have a reliable base to get them nominations, but those people (democrats) vote for the democrat in November. This has been the game for years, to shut conservatives out of public office, and feeds the meme “conservatives can’t get elected, or are unelectable” and thus, types like McCain and Romney and their ilk are always called “electable.”
“Do GOP “moderates” have any reliable base?”
They don’t need one, the money is too good from their corporate masters. Hell, they don’t even want to govern anyway.