Arizona Democratic Sen. Ruben Gallego is leading an effort to overturn a Trump administration policy that critics argue could require hundreds of thousands of green card applicants to leave the United States and complete parts of the immigration process from abroad.

According to a report by The Hill, Gallego’s push extends beyond opposing the policy itself. He is also seeking to have the action formally classified as a federal rule, a move that could provide Congress with a potentially easier mechanism to challenge or reverse it.

The dispute centers on both immigration policy and the process used to implement it. By pursuing a formal rule designation, Gallego is attempting to open an additional avenue for congressional review and possible intervention.

Supporters of stronger immigration enforcement have long argued that clear procedures and adherence to legal requirements are essential for maintaining the integrity of the immigration system. Critics of efforts to weaken such policies, meanwhile, contend that lawmakers often look for procedural shortcuts when they cannot win the broader policy debate outright. Washington, after all, never seems to run out of creative ways to fight the same battles twice.

The debate is expected to continue as lawmakers weigh the future of the policy and Congress considers what role it should play in reviewing executive actions related to immigration. As the discussion moves forward, the issue is likely to remain a major point of contention in the ongoing national debate over immigration and border security.