In 1974 Fulbright encountered political opposition in Arkansas from an unexpected source – its progressive and immensely popular governor, Dale Leon Bumpers. Bumpers viewed the governor's office as a political graveyard and very much wanted to go to Washington. Fulbright had failed to make his preemptive tour of the state in early 1973, and Bumpers and his advisers sensed, correctly, a weakening of political will. They were not alone. Indeed, preliminary polls indicated that any one of a number of people, including Orval Faubus, could beat the incumbent junior senator in 1974. To save Arkansas and the national Democratic Party from the humiliation of Faubus in the Senate, and to realize his own ambition, Bumpers decided to challenge Fulbright.

The incumbent was never in the race. Arkansans were angry with Fulbright for his stands on Vietnam, the Middle East, and Watergate and for his perceived neglect of the state. The junior senator was ill at ease with the campaign techniques necessary to win in the new media age, whereas the challenger was perfectly at home with them. Bumpers was conservative enough to satisfy those on the political right and liberal enough to please those on the left. As a result, on election day he outpolled the state's most famous citizen by 320, 798 to 174, 734.

Fulbright's defeat was mourned and cheered around the nation and the world. Scoop Jackson's staff broke out a case of whiskey in celebration. As news of Fulbright's resounding defeat came across the wire services in Phnom Penh, members of the American embassy staff stood in their chairs and cheered wildly.