Rep. Mullin Strong Favorite in Oklahoma Senate Runoff In the Republican primary that is tantamount to election to the seat of Oklahoma's retiring GOP Sen. Jim Inhofe, the top two vote-getters Tuesday were Rep. Markwayne Mullin and former state House Speaker T.W. Shannon — both stalwart conservatives and strong supporters of former President Donald Trump. But with Mullin drawing 44% of the vote in a 13-candidate race, he remains the strong favorite over Shannon (18%) in the runoff Aug. 23.