Senator Jackson made a fateful decision not to compete in the early Iowa caucus and New Hampshire primary, which Jimmy Carter won after liberals split their votes among four other candidates. Though Jackson went on to win the Massachusetts and New York primaries, he was forced to quit the race on May 1 after losing the critical Pennsylvania primary to Carter by twelve percentage points. Carter then defeated Governor Wallace, his main conservative challenger, by a wide margin in the North Carolina primary, thus forcing Wallace to end his campaign. Representative Udall, a liberal, then became Carter's main challenger. He finished second to Carter in the New Hampshire, Massachusetts, Wisconsin, New York, Michigan, South Dakota, and Ohio primaries, and won the caucuses in his home state of Arizona, while running even with Carter in the New Mexico caucuses. However, the fact that Udall finished second to Carter in most of these races meant that Carter steadily accumulated more delegates for the nomination than he did.