Alabama Sen. Tommy Tuberville is waging an unprecedented campaign to try to change Pentagon abortion policy by holding up hundreds of military nominations and promotions, forcing less experienced leaders into top jobs and raising concerns at the Pentagon about military readiness.

Senators in both parties – including Republican Leader Mitch McConnell – have pushed back on Tuberville’s blockade, but Tuberville is dug in. He says he won’t drop the holds unless Democrats allow a vote on the policy.

For now, the fight is at a stalemate. Democrats say a vote on every nominee could tie up the Senate floor for months. And they don’t want to give in to Tuberville’s demands and encourage similar blockades of nominees in the future.