The impetus for national adoption of the binding primary election was the chaotic 1968 Democratic National Convention . Vice President Hubert Humphrey secured the Presidential nomination despite not winning a single primary under his own name . After this , a Democratic National Committee-commissioned panel led by Senator George McGovern – the McGovern – Fraser Commission – recommended that states adopt new rules to assure wider participation . A large number of states , faced with the need to conform to more detailed rules for the selection of national delegates , chose a presidential primary as an easier way to come into compliance with the new national Democratic Party rules . The result was that many more future delegates would be selected by a state presidential primary . The Republicans also adopted many more state presidential primaries . By 1992 , Democrats had primaries in 40 states and Republicans in 39
1968 Democratic National Convention
1968 Democratic National Convention
United States presidential primary