In the presidential election of 1800, Thomas Jefferson and Aaron Burr, both Democratic-Republicans, win 73 votes in the Electoral College, forcing the House of Representatives to choose the president and vice president. The House eventually votes for Jefferson as president after a protracted deadlock. Ballots are cast 36 times by the House, and the vote is still tied. Then, one Federalist, Alexander Hamilton, changes his vote. Others follow, and Jefferson is elected president on the 37th ballot. This event triggers the demand for the 12th Amendment.