Brian Higgins of Wisconsin had pled guilty to a charge of attempting to provide material support of terrorism and faces up to five years in prison.
He will affirm against the four different men charged in the plot to seize lead representative Whitmer in 2020, with that preliminary set to begin in August.
Prior to entering the plea, Higgins faced up to 20 years in prison.
After the August trials of the other four, his sentence will be handed down.
