The establishment of the direct primary in wisconsin was one reform that allowed citizens to select nominees for upcoming elections.

The establishment of the direct primary in Wisconsin was one  PROGRESSIVE REFORM  that allowed citizens to select nominees for upcoming elections.

Progressive reforms refers to the efforts that made to reduce the power of the government establishment and give it back to the people. 
The citizen of united states will have much more influence in the government if they could personally select nominees for upcoming elections. and not let it be controlled by political parties.