He came fourth in the Democratic primary with 84,404 votes (15.80%), behind National Commander of the American Legion Preston J. Moore, businessman W. P. Atkinson and former Governor Raymond Gary. Atkinson went on to win the runoff and lose the general election to Republican Henry Bellmon, but Nigh would get a chance to serve as governor. Democratic U.S. Senator Robert S. Kerr died in office on January 1, 1963 and Edmondson resigned his office 5 days later; Nigh succeeded him as governor for the remaining days of the term only to appoint him to the vacant Senate seat. On 14 January, Bellmon took office as governor. Nigh ran for Lieutenant Governor again in 1966. He was unopposed in the Democratic primary in this and his re-election efforts, winning in 1966 with 328,580 votes (51.50%); in 1970 with 382,249 votes (57.41%) and in 1974 with 545,686 votes (72.36%). In 1970 he beat future district judge Ralph Gordon Thompson. Nigh served as the tenth lieutenant governor from January 9, 1967 to January 3, 1979, making him the second longest-serving Oklahoma lieutenant governor in state history with 16 years of service. In 1969, during his time serving as Lieutenant Governor, Nigh assisted a number of college students with the creation and founding of the “Oklahoma Intercollegiate Legislature” (O.I.L.), which still functions today as a collegiate model government program with delegations at over 20 colleges and universities across the state. When incumbent governor David Boren chose not to seek reelection, Nigh ran for Governor again in 1978. He came first in the Democratic primary with 276,910 votes (49.94%), narrowly short of avoiding a runoff against Oklahoma Attorney General Larry Derryberry, who took 208,055 votes (37.53%). However, in the runoff, Nigh defeated him easily, with 269,681 votes (57.73%) to Derryberry's 197,457 (42.27%). Nigh defeated Republican Ron Shotts in the general election with 402,240 votes (51.74%) to Shotts' 367,055 (47.22%) and thereby became the first Oklahoma Governor to serve a second term. Nigh took office five days early, as a result of outgoing Governor David Boren's swearing-in as a U.S. Senator. He ran for a second term in 1982 becoming the third Governor to do so, and defeated token opposition in the Democratic primary with 379,301 votes (82.63%) as well as Republican State Auditor Tom Daxon in the general election by 548,159 votes (62.07%) to 332,207 (37.62%), carrying all 77 of the state's counties. It was