"It's a parent's right to be able to medicate and educate their children how they see fit," said Howell, who is a veterinarian.

Yen, who is a medical doctor, was the only incumbent state senator to lose reelection.

Incumbent Sen. Ervin Yen, R-Oklahoma City, lost his reelection on Tuesday, falling to challenger Joe Howell in the Senate District 40 Republican primary.

Howell, who beat Yen by nearly 20 percentage points, will face Carri Hicks, who edged out Danielle Ezell in the Senate District 40 Democrat primary.

Hicks, who is a fourth-grade teacher, beta Ezell by two percentage points.

Senate District 40, located in northwest Oklahoma City, includes parts of state House seats that Democrats have flipped in recent years.

Democrats view the district as one of its best chances to flip a Senate seat in the November general election.