Has a court ever struck down an election result in the United States?

Answer 1

In the United States we have both the federal court system as well as state courts. While the U.S. supreme court has intervened in federal elections (Bush v. Gore) it has never struck down an election result. At the state level, election results have been overturned. This can happen for multiple reasons but usually is due to fraud. Voter suppression, absentee voter fraud, illegal campaign funds etc are all examples of voter fraud that could derail an election.