Could we reverse a hacked presidential election?

Very interesting, but no proposals on how to keep it from happening to begin with.
Secondly, what do they mean by 'hacked?'
Everything that the opposition (primarily the Democratic Party) is trying to prevent as suggested by others, such as Voter ID, mandatory audit features in machines and other such methods.
Interesting but in a utopian world results such as what happened in Detroit and other locations would automatically be rejected. But what is interesting about some of this, in Detroit they tried to place the blame on 80 broken machines, and on older workers at the polls. Interesting but they threw their own people under the proverbial bus.
"The Free Press analysis found there were 248 precincts in Detroit where voting machines tabulated more Election Day votes than people who were counted as checking in to vote. The affected precincts represent 37% of the city's 662 precincts.
In 158 precincts, the number of ballots tabulated by the optical-scanning voting machines was inexplicably less than the number of people who signed in to vote. At least 362 ballots were not counted in those precincts, even though the voters had been listed in the poll books."

Added after initial posting - "According to state law, precincts whose poll books don’t match with ballots can’t be recounted. If that happens, original election results stand." That's for Michigan.