Unless something has changed, the Democrat Governor of Virginia–I believe him name is Terry McAuliffe, who is also the person who donated so generously to the political campaign of the wife of the FBI agent who supervised the investigation of Hillary–granted voting rights to convicted felons unilaterally and in defiance of Virginia law, after which the Supreme Court of Virginia told him he did not have the right to do that, and he is currently ignoring them. [He is, in other words, either refusing to uphold his oath of office, or breaking the law outright.]
None of those votes have legal standing. Hopefully, Trump will win in a landslide, but if he does not, the legitimacy of those votes can and should be challenged, if the vote totals are within the margin allowed by the votes potentially cast by people not legally allowed to do so.
This is common sense.
And the law. Let’s not forget that we are theoretically a nation of laws, even if evidence for that claim becomes scantier year by year, and as institutions are infected by contact with people like the Obama’s and Clintons.