1966 United States Senate election in Oklahoma

James Howard Edmondson was an American politician from the U.S. state of Oklahoma. He served as the 16th governor of Oklahoma from 1959 to 1963, and the appointed United States Senator from Oklahoma from 1963 to 1964, losing to Fred R. Harris in a 1964 special election for the U.S. Senate. When he took office as Governor of Oklahoma at the age of 33, Edmondson was, and still is, the youngest governor in the history of the state.

Fred Roy Harris is an American academic, author, and former politician who served as a Democratic member of the United States Senate from Oklahoma.

Raymond Dancel Gary was an American businessman and politician who served as the 15th governor of Oklahoma from 1955 to 1959 and the first governor to be born in Oklahoma since statehood.

The Democratic Party is one of two major contemporary political parties in the United States. Founded in 1828, it was predominantly built by Martin Van Buren, who assembled politicians in every state behind war hero Andrew Jackson, making it the world's oldest active political party. Its main political rival has been the Republican Party since the 1850s, with both parties being big tents of competing and often opposing viewpoints. Modern American liberalism — a variant of social liberalism — is the party's majority ideology. The party also has notable centrist, social democratic, and left-libertarian factions.

The Democratic Party is one of two major contemporary political parties in the United States. Founded in 1828, it was predominantly built by Martin Van Buren, who assembled politicians in every state behind war hero Andrew Jackson, making it the world's oldest active political party. Its main political rival has been the Republican Party since the 1850s, with both parties being big tents of competing and often opposing viewpoints. Modern American liberalism — a variant of social liberalism — is the party's majority ideology. The party also has notable centrist, social democratic, and left-libertarian factions.

Fred Roy Harris is an American academic, author, and former politician who served as a Democratic member of the United States Senate from Oklahoma.

The Republican Party, also referred to as the GOP, is one of the two major contemporary political parties in the United States. The GOP was founded in 1854 by anti-slavery activists who opposed the Kansas–Nebraska Act, which allowed for the potential expansion of chattel slavery into the western territories. It has been the main political rival of the Democratic Party since the mid-1850s. Like them, the Republican Party is a big tent of competing and often opposing ideologies. Presently, the Republican Party contains prominent conservative, centrist, populist, and right-libertarian factions.

In political science, voter turnout is the participation rate of a given election. This is typically either the percentage of registered voters, eligible voters, or all voting-age people. According to Stanford University political scientists Adam Bonica and Michael McFaul, there is a consensus among political scientists that "democracies perform better when more people vote."