President Trump’s budget proposed Tuesday calls for a new round of military base closures in 2021, a plan likely to add to the numerous objections to the budget coming from Congress.

The budget as a whole is facing fierce opposition ranging from defense hawks who want higher Pentagon spending to Democrats lambasting steep cuts in domestic spending.

Base Realignment and Closure (BRAC) has in the past drawn fierce opposition from lawmakers worried about the economic effects of the closures on their communities.

{mosads}Pentagon leaders have for years requested a new round of BRAC as a way to save money, but Congress has repeatedly prohibited it in defense policy and spending bills.

In the budget documents released Tuesday, the administration says the Department of Defense (DOD) has about 20 percent excess infrastructure capacity across all military branches. It estimates a BRAC round could save $2 billion or more by 2027 and argues the process is the “best way to eliminate” the excess capacity.

“By executing BRAC in 2021, DOD will have the opportunity to reduce unnecessary infrastructure and align its facilities with the force structure determined by the National Defense Strategy,” the documents say.

The last BRAC round was in 2005, and critics of that round said it cost too much upfront and took too long to see savings. It included both a “transformation” BRAC, which cost $29 billion and saves about $1 billion annually, and an “efficiency” BRAC, which cost $6 billion and saves $3 billion annually.

But BRAC appeared to gain some momentum earlier this year when the leaders of the Senate Armed Services Committee said they supported it as a way to find money to channel back into military capability.

Still, some decision-makers on BRAC remain hesitant. On Monday, Rep. Mac Thornberry (R-Texas), chairman of the House Armed Services Committee, questioned whether closing bases would have negative effects on civil-military relations. 

“We talk a lot about BRAC, and there’s a lot of ways to evaluate it,” he said at a Brookings Institution event. “If you significantly reduce the number of communities that have military bases near them, how does that affect the relationship between civilian sector and the military? Or does it? It may.”