I don't think it will matter at this point if he is convicted. 55% of Americans believe the prosecutions against him are politically motivated, and that number seems to be going up every time a new indictment is introduced, not down. There's even almost 20% of Democrats who are willing to admit publicly that they believe that. Convicting him might sway most Dems and some independents against voting for him, but the working class MAGA base will only be more determined. At this point, they'll vote for Trump in a jail cell or they won't vote. No other Republican would be viable even if Trump dropped out of the race tomorrow.

As for rigging the election, the renewed COVID panic being propagated by the state-media complex is clearly intended to lay the groundwork for mass harvesting mail-in ballots again, but it really looks like the only places where it will work are already deep blue. I don't think people in the swing states where they need to pull the most bullshit will tolerate another million or three mail-in ballots.