Trump would probably be indicted by a prosecutor with either manslaughter or second-degree murder in this scenario, and might be denied bail, so I don't think he'd be able to campaign.
That's a great point! It depends on the state, but you can be prosecuted for purposely exposing others to contagious diseases with specific statutes or general criminal laws- according to the DOJ, COVID meets the statutory definition of a biological agent, so it could even be a terrorism charge. The ensuing court case would be even more monumental than the election, I think. Anti-maskers would consider a guilty decision to be a violation of individual rights on the level of the PATRIOT Act (probably with that exact wording), while the more polished Republicans would just dispute that Trump intended to spread the disease to Biden (with his inevitable statements not helping their case). The decision could spark riots that would make the Storming of the Capitol look like nothing.
