Oklahoma Senator James Lankford faces two Republican challengers in the primary; Jackson Lahmeyer and Joan Farr.
Lankford and his wife voted in Oklahoma City on Tuesday morning. "It's a job interview, and Oklahomans today are deciding who they're going to hire to be the next senator, to be able to move on to November, and to be able to move on from there. So, today's the day people start making their decisions and I'm one of those making decisions today," Lankford said about voting on Tuesday.
According to the latest Sooner Poll taken at the end of May, Lankford has a lead on his opponents.
The poll of 300 likely Republican primary voters had Lankford sitting at 73.6 percent.
Lahmeyer, a Tulsa pastor, was noted at 8.1 percent.
Joan Farr polled at 2.2 percent.
The amount of undecided voters came to 16.1 percent.