All members of Oklahoma's Congressional delegation have challengers, according to the Oklahoma State Election Board.
The filing period for federal, state and legislative offices in Oklahoma for the November general elections ends at 5 p.m. on Friday, April 15, 2016. As of 4 p.m., all members of the delegation had at least two challengers.
Incumbent Republican James Lankford is running for re-election to the U.S. Senate. His challengers are Democrats Steve Perry of Oklahoma City and Mike Workman of Tulsa, Libertarians Dax Ewbank of Guthrie and Robert Murphy of Norman and Independent Sean Braddy of Norman.
In the race for U.S. Representative District 1, incumbent Republican Jim Bridenstine has two Republican challengers -- Evelyn Rogers and Tom Atkinson, both of Tulsa -- and one Independent challenger, David Hullum of Tulsa.
In District 2, incumbent Republican Markwayne Mullin faces Republican Jarrin Jackson of Claremore, Democrats Paul Schiefelbein and Joshua Harris-Till of Tahlequah and Independent John McCarthy of Afton.
In District 3, incumbent Republican Frank Lucas faces a challenge from fellow Republican Desiree Brown of Hennessey, as well as Democrat Frankie Robbins of Medford.
In District 4, incumbent Republican Tom Cole faces Republicans James Taylor of Norman and Shawn Roberts of Lawton, as well as Democrat Bert Smith of Moore and Libertarian Sevier White of Norman.
In District 5, incumbent Republican Steve Russell faces fellow Republican Frank Volpe of Harrah, Democrats Tom Guild of Edmond, Al McAffrey of Oklahoma City and Leona Leonard of Seminole as well as Libertarian Zachary Knight of Edmond.