What makes the charge idiotic is President Donald Trump had no way to overturn the results. Now, if he ordered the National Guard to seize the ballots, that would have been a basis for charging him. He did no such thing or even interfered in the counting of the ballots. Asking to investigate possible election fraud is not against the law. A number of US citizens tried to challenge it in US courts but, when the US courts turn a blind eye to fraud, there is not much you can do about it.
Pressuring election officials to lie and invalidate election results is against the law -- in every f@cking state and federally.