All any Republican primary opponent has to do is say "Mario Cuomo" and Rudy is done.
Rudy backing Cuomo in the closing days of the 1994 election was surprising and unforgiveable.
Rudy got caught with his pants down, too - Pataki won, and Rudy was not an A-List person in Albany.
At the time, I reflected upon it and I can see how it was a very self serving thing for him to do. Rudy's job was to win in NYC, where backing Cuomo would be seen as a plus. Further, the polls all had it 'close' with a slight edge to Cuomo in the closing days, and Rudy's backing of Cuomo could have been seen throughout the state as a 'minus' for Cuomo and maybe even cost him the race.
In any event, Cuomo was tired and hackneyed as election day 1994 rolled around - he was shooting for his 4th term, and people just got tired of him. Pataki will be shooting for his 4th term if he runs again - hard to imagine he can pull it off, though has consistently been a decent Governor for NY - compared to Cuomo he is an angel.