They don't need to vote dem, they just need to lose motivation to vote (either not vote at all, or vote for anyone non-GOP). The GOP cannot afford to lose many votes, so long as the elections are fair, as you say. The elections will happen in some shape or form (remember, even Russia has """elections"""). The GOP has seats up for election and upcoming vacancies.
It's just a matter of how fair they'll be.
For many reasons, unfortunately Buttigieg is a better candidate than Newsom. That's kind of sad.