by tradition which state’s caucus is the first presidential contest held every four years
United States presidential primary The first binding event, in which a candidate can secure convention delegates, is traditionally the Iowa caucus, usually held in late January or early February of the presidential election year. It is generally followed by the New Hampshire primary, the first primary by tradition since 1920 and by New Hampshire state law. New Hampshire law states the primary shall be held "on the Tuesday at least seven days immediately preceding the date on which any other state shall hold a similar election." The Iowa caucuses are not considered to be "a similar election" under New Hampshire's law because the former uses caucuses instead of primary elections. Should any other state move its primary too close to New Hampshire's, or before, the New Hampshire Secretary of State is required to reschedule the primary accordingly.[34]
United States presidential election, 2016 Voters selected members of the Electoral College in each state, in most cases by "winner-takes-all" plurality; those state electors in turn voted for a new president and vice president on December 19, 2016.[a] While Clinton received over 2.8 million more votes nationwide, a margin of 2.1%, Trump won 30 states with a total of 306 electors, or 57% of the 538 available. He won two perennial swing states which typically decide an election, in Florida and Ohio. Trump also won three "blue wall" stronghold states that had not gone Republican since the 1980s: Michigan, Pennsylvania, and Wisconsin. He also won Maine's 2nd congressional district, which had also not been won by a Republican presidential candidate since 1988. Leading up to the election, a Trump victory was considered unlikely by almost all media forecasts. After his victory was assured, some commentators compared the election to President Harry S. Truman's victorious campaign in 1948 as one of the greatest political upsets in modern American history.[14][15]