In the 1976 presidential election, Ford was challenged by Ronald Reagan, a leader of the conservative wing of the Republican Party. After a contentious series of primaries, Ford won his party's nomination at the 1976 Republican National Convention. In the general election, Carter defeated Ford by a narrow margin in the popular and electoral vote. They lost repeatedly in the federal courts, most notably in the 1976 Supreme Court decision of Kleppe v. New Mexico. Ford's successes included the addition of two national monuments six historical sites, three historic parks and two national preserves.