As the nation’s top civil rights attorney, Thomas Perez made disability issues a priority. His nomination this week to head the U.S. Department of Labor, however, is bringing an uncertain future for disability rights enforcement.

President Barack Obama nominated Perez Monday to be the next secretary of labor. If confirmed, the move would leave Perez’s current job as assistant attorney general of the civil rights division at the U.S. Department of Justice wide open.

Since he was confirmed to the post in 2009, Perez has taken on disability rights head first. Under his leadership, the Justice Department has participated in legal actions in more than two-dozen states to uphold the rights of those with disabilities to live in the community whenever possible, in addition to bringing first-ever hate crimes charges on the basis of disability.

“It’s really been night and day,” said Curt Decker, executive director of the National Disability Rights Network, of the Justice Department’s efforts under Perez as opposed to his predecessors. “He really has built the department and made them extremely aggressive on disability issues.”

Decker, who’s group is an umbrella organization for the protection and advocacy organizations in each state, said Perez has been an ally to disability advocates, not only by bringing cases, but also backing existing ones.

Under previous administrations, Decker said federal prosecutors would often identify problems at state-run institutions and reach settlements forcing the states to pump millions of dollars into fixing the facilities. By contrast, under Perez, states including Virginia and Georgia have agreed to essentially dismantle their institutionally-focused systems for people with disabilities and establish a complement of community-based offerings.

Beyond that, Perez’s division has pursued cases to ensure accessibility of sidewalks, hotels and stadiums. They’ve taken a stand against unnecessary segregation in sheltered workshops and his department worked to clarify the rights of students with disabilities to bring service dogs to school, among other issues.

Perez’s efforts have stretched far beyond the people directly affected by the cases the Justice Department has pursued under his tenure, said Mark Perriello, president and CEO of the American Association of People with Disabilities.

“It’s a huge impact not only because more people can live independently, but to see enforcement is really empowering and energizing,” Perriello said.

Next up, Perez will go before the U.S. Senate in a bid to be confirmed as the next labor secretary, a process which could be contentious amid concerns from Republicans that decisions — specifically on voting rights issues — were ideologically driven under his tenure at the Justice Department.

If confirmed, disability advocates say they are optimistic that Perez will be a strong voice for those with disabilities at the Labor Department, perhaps addressing issues like subminimum wage and the use of sheltered workshops.

Who might take Perez’s place at the Department of Justice is unclear, though both Decker and Perriello said they believe the Obama administration’s commitment to disability rights enforcement comes from the top and will outlive any one appointee.

“I think the next person will have very big shoes to fill,” said AAPD’s Perriello. “It’s my hope that there will be a similar emphasis under whoever comes in after Tom, but there are no guarantees.”