I'm not sure Reagan would have won in November either.
While it would have been harder to tie him to Nixon, it would have been easier for Carter to attack him as an extremist (which he tried to do in 1980 and failed because the fundamentals were so heavily against Democrats).
It would have come down to running mate choices. If Reagan picks a conservative, like Dole, he loses, but if he picks a moderate like Schweiker or Javits, he wins.
Either way, Carter probably wins the popular vote by a very slim margin.
Reagan's VP pick is a double-edged sword. If he picks Dole, he doubles down on conservatism, further alienating moderates; if he picks Schweiker (as he was set to do), it's seen as a betrayal by conservatives (as it actually was) and he also probably can't convince enough moderates to turn out for him since Reagan's at the top of the ticket. Reagan probably loses, and by a decent margin too.
