Senator Tommy Tuberville of Alabama has blockaded promotions to top military positions to protest the Pentagon's policy on reproductive healthcare, including abortion.
As a result of Tuberville's protest, the United States Marine Corps is without a confirmed leader for the first time in 164 years.
Approximately 265 military positions are currently in limbo due to Tuberville's refusal to confirm promotions.
General David Berger, the commandant of the Marine Corps, retired without a congressionally approved replacement.
General Eric Smith will serve as the acting commandant of the Marine Corps until promotions resume in the Senate.
The last time the Marines' leadership failed to have an official successor was in 1859 when the commandant at the time died unexpectedly.
The upcoming retirement of nearly half of the Joint Chiefs of Staff, the highest leaders in the Department of Defense, could result in vacancies being filled without Congress's consent.
Tuberville's actions have received criticism from both Democrats and Republicans, with some expressing concerns about the impact on military preparedness.
Senator Mitch McConnell, the Senate Republican leader, stated that he does not support putting a hold on military nominations.
Tuberville's blockade has sparked controversy and raised questions about the role of abortion policy in military promotions and leadership.