Politicians make a terrible mistake by trying to discredit the upcoming election before votes have even been cast. President Trump pre-emptively denounces the election as “rigged” and “fraudulent”, while prominent Democrats question whether the president will leave office even if he loses. These speculations only discourage electoral participation: who wants to bother with voting if you’ve come to believe the entire exercise is corrupt and meaningless?
This doesn’t mean that either side should abandon vigilance when it comes to voter fraud, but the presidential candidates certainly understand that under the Constitution, each state can make its own decisions about how to conduct their balloting.
The best way to avoid a disputed outcome – with all the polarization and instability that would entail – is to see a decisive victory for one side or the other. That means encouraging your supporters to register, and to vote, in overwhelming numbers, not to denigrate the act of voting by demeaning the electoral process.