Do the "tell that to Rick Santorum" people understand that a "trend" =/= "set in stone rule that must never be broken?"
Since Eisenhower, only 2 people have won the Republican nomination without being one of the following things:
-Incumbent President (Ike '56, Nixon '72, Ford '76, Reagan '84, Bush '92, Bush '04)
-Former VP (Nixon '60, Nixon '68)
-Son of former President who was also Governor of a major state (Bush '00)
-Runner-up in last primary without an incumbent (Reagan '80, Bush '88, Dole '96, McCain '08, Romney '12)
The two nominees not falling under one of these were Goldwater and, presumably, Trump. Leaders of major wings of the party (Goldwater with conservatives, Trump with Trumpists).
So, if the nominee in 2020 must be one of those 4 things, and the Democrat (read: Hillary) wins, it can only be: Ted Cruz, Jeb!, Dick Cheney, Dan Quayle, or, technically, George H. W. Bush. Realistically, it could only be the first two. But, even more realistically, I think another person will break this trend in 2020.
The hope is that the GOP will learn their lesson once Trump is destroyed, and move far to the center, but this is the GOP so who knows.
Er...what? Outside of immigration, Trump is very moderate. This whole "Trump is far right" thing has been disproven over and over again. I agree that Trump will do poorly, but it will NOT be due to him being "too conservative." (Or him being "too moderate," in case that meme comes up here soon.)