Same thing happened in 1980 when a lot of Jerry Ford and Rockefeller types said that Ronald Reagan was far too extreme so they were voting for Jimmy Carter. Big news for the MSM but poor Jimmy got no good out of it!
Really? Who? More Democrats bailed on Carter than Republicans did on Reagan.
Something like that did happen in 2008 and 2012 and that really did hurt McCain and Romney, but I don't remember it happening in 1980.
Sure, John Anderson, a Republican Congressman did run as an independent, but with Bush and Baker on board, Reagan didn't have much trouble with Ford and Rockefeller types.