You forgot about Bush vs Buchanan in NH during 1992. At least McCarthy was a senator. Buchanan was a political columnist, and he beat Bob Dole in NH in 1996.
You are correct, thanks for pointing those examples out, especially as it reinforces my theory that a nominee/sitting president that does poorly in the primaries tends to do poorly in November. Both Bush in 1992 and Dole in 1996 went on to lose badly as the GOP failed to heed the warning signs that even a political columnist could beat their candidates in a primary - but they went ahead and nominated them anyhow.