Nixon ran six years after losing the CA Governor’s race.
Anyone who just lost five months ago is not a good POTUS bet this time.
The point being, Nixon got nominated over Reagan. But, like Nixon, Reagan never quit trying.
By your logic he was a proven loser, but now you adding new qualifications to your statement.
And I wasn’t holding up Nixon as a conservative example, but as an example of someone that came back from losing 2 major elections to take the Presidency.