WASHINGTON (AP) — The Supreme Court has ruled unanimously that states can require presidential electors to back their states’ popular vote winner in the Electoral College.

Monday's ruling, just under four months before the 2020 election, leaves in place laws in 32 states and the District of Columbia that bind electors to vote for the popular-vote winner.

Electors almost always do so anyway.

So-called faithless electors have not been critical to the outcome of a presidential election, but that could change in a race decided by just a few electoral votes. It takes 270 electoral votes to win the presidency.

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