Chiafalo v. Washington

Washington presidential electors Chiafalo, Guerra, and John (plaintiffs) pledged to vote for Hillary Clinton but instead voted for Colin Powell in the 2016 election, hoping to encourage other electors to abandon Donald Trump; Washington fined each elector $1,000 under a state pledge law, and the electors sued, arguing the Constitution gives electors unconditional discretion to vote as they choose, making the fines unconstitutional. The Washington courts upheld the fines, and the electors appealed to the Supreme Court.