The U.S. presidential election system is not decided by the popular vote but by the Electoral College. Candidates vie for a total of 538 electoral votes, with 270 needed for victory. Most states operate under a winner-takes-all system, awarding all electoral votes to the candidate with the highest vote count. This makes swing states crucial, as they can sway the election results despite strong party affiliations in most states. Notably, candidates can win the nationwide vote yet lose the election, as seen in Hillary Clinton’s 2016 campaign.