Nelson Rockefeller won all his races for NY governor by at least 6 points. How can he lose?
He won with less than a majority in 1966. Get the Liberal Candidate (FDR Jr) to drop out in favor of the Democratic nominee, Frank O'Connor. Maybe bump up the Conservative Party vote a little.
Would Rockefeller successfully winning the Republican nomination, but losing the general election very badly, in 1964 hurt him two years later? Especially if the reason he won the nomination was that his divorce scandal gets delayed until 1965 when it all breaks?