Abdnor:      40-50%      50-60%      60-70%      70-80%      80-90% George McGovern Democratic James Abdnor Republican Measure 9 Amendment A Amendment E Amendment G The 1980 United States Senate election in South Dakota was held on Tuesday November 4, Incumbent United States Senator George McGovern ran for re-election to a fourth term, but was defeated by Republican James Abdnor.

[2] They and other anti-abortion groups especially focused on McGovern's support for pro-choice abortion laws.

[3] McGovern made an issue of NCPAC's outside involvement, and that group eventually withdrew from the campaign after Abdnor denounced a letter they had sent out.

[6] McGovern became one of many Democratic casualties in that year's Republican sweep,[7] which became known as the "Reagan Revolution".

McGovern was one of nine incumbent Senators to lose a general election that year, and his margin of defeat was by far the largest until Blanche Lincoln was unseated by John Boozman in 2010.