A federal appeals court ruled late Tuesday that presidential electors who cast the actual ballots for president and vice president are free to vote as they wish and cannot be required to follow the results of the popular vote in their states, NBC News reported.

The decision could give a single elector the power to decide the outcome of a presidential election — if the popular vote results in an apparent Electoral College tie.

"This issue could be a ticking time bomb in our divided politics. It's not hard to imagine how a single faithless elector, voting differently than his or her state did, could swing a close presidential election," said Mark Murray, NBC News senior political editor.

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