The framers gave the Electoral College broad discretion to resolve disputes as it saw fit: The text of the Constitution pretty much says an election is legitimate when the Electoral College says it is. It doesn’t lay out a process for do-overs. Occasionally, courts have ordered new elections for offices other than the presidency after a proven case of fraud or error. (Or gerrymandering — a court in North Carolina ordered new state legislative elections, though this order has been put on hold.) And a Senate election was once redone in New Hampshire because it was too close to determine even with multiple recounts.
But whether this kind of re-do is allowed for presidential elections is a more complicated matter. Some legal scholars maintain that the language in Article II of the Constitution prevents holding a presidential election again, thus putting it beyond the power of the courts to order a re-vote, as they have occasionally done for other offices. Others suggest that there is legal precedent for a presidential re-vote if there were flaws in the process. One instance in which this question arose was the “butterfly ballot” from the 2000 election, which may have caused some voters to choose Pat Buchanan when they meant to vote for Al Gore in Palm Beach County, Florida.2