Since the 1930s, a critical component of the Democratic Party coalition has been organized labor. Labor unions supply a great deal of the money, grassroots political organization, and voting base of support for the party. Union membership in the United States has declined from an all-time high in 1954 of 35% to a low of 11% in 2015. After the 1968 Democratic National Convention, the McGovern–Fraser Commission set up the modern system of primaries. It also removed organized labor from its structural position of power in the Democratic Party and opened it up democratically to the voters.