Put these few facts together:
Democratic candidates are more likely to win when large numbers of people vote.
In a number of states ruled by Republicans, those states do several things to reduce voter turnout — and to make it hard for racial minorities, young people, and poor people to vote, because those people tend to vote for Democrats.
Voting by mail significantly increases voter turnout. Trump and Republicans strongly oppose this, because they want to SUPPRESS voter turnout.
The Coronavirus pandemic makes it dangerous to vote in person (in the 45 states that do not have voting by mail).
Trump supporters and Republicans are more likely to be “deniers” about Coronavirus and less likely to wear masks.
They will turn out in person to vote in November, regardless of the dangers.
Democrats and other sensible people are less likely to vote in person if the pandemic is still dangerously raging.
Therefore, Trump and Republican governors WANT TO KEEP THE PANDEMIC RAGING into November.
Sensible people will STAY HOME, but hard-core Trump cult loyalists and Republicans will turn out to vote anyway.
THEREFORE, Trump and Republicans want to KEEP THE PANDEMIC RAGING in order to increase their likelihood of winning in November 2020.