WASHINGTON — The House Armed Services Committee’s top Democrat is pushing back on a proposal to shutter seven Pentagon support agencies and slash 25 percent from the budgets of most of the others.

Washington Democratic Rep. Adam Smith said he had “serious concerns” about the impact HASC Chairman Mac Thornberry’s new proposal would have. Thornberry introduced a bill Tuesday aimed at reducing bureaucratic waste at DoD and guiding the Pentagon’s internal reform efforts.

“It appears this proposal could do serious damage to DoD’s information infrastructure, testing ranges, and community support, as well as the basic DoD functions in the National Capital Region by eliminating critical agencies in one stroke,” Smith said in a statement Wednesday.

Smith, often a voice for restraint in defense spending, called for further analysis before cutting services that might impact troops’ quality of life, “as well as on thousands of jobs across the country.”

Smith’s statement set the stage for a HASC hearing Wednesday on the value of “fourth estate” agencies where Democrats took their lead from Smith and expressed similar concerns.

Also — a day after Thornberry suggested there may be $25 billion that could be reinvested in war fighting — witnesses said the effort is important, but threw cold water on the idea there was that much savings to be found.

The House bill would look to impose a mandatory 25 percent spending cut for a group of 28 agencies and, and in the process, eliminate seven specific entities, including the Defense Information Systems Agency. Should the 25 percent savings not be met by a January 2021 deadline, it would trigger a 25 percent across-the-board cut.

“As we are working to get more value for the taxpayer dollar, to get more resources into the hands of the warfighter faster, and to make the department more agile and innovative in facing the wide array of security challenges before us, we cannot neglect to examine this large portion of DoD,” Thornberry said.

Thornberry aims to add the language to the House’s 2019 National Defense Authorization Act, set to be debated in early May before a House vote and reconciliation with a Senate version. After the hearing, Thornberry said he was open to adjustments.

Because much of DoD’s “fourth estate” spending resides in combat-support and intelligence agencies that Thornberry would exempt from the cuts, there’s not much left over that would be easy to cut, said witness Peter Levine, a former DoD deputy chief management officer now with the Institute for Defense Analyses.

“I don’t meant to imply there are no efficiencies possible, but if we’re looking at the rest of it, we have a quarter of the fourth estate left to look at,” Levine said. “You can’t achieve a 25 percent reduction when you look at only a quarter of the budget.”

Witness Preston Dunlap, the former chief of staff at DoD’s Cost Assessment and Program Evaluation office, said that if all seven agencies were eliminated, it would amount to a roughly 2 percent cut, adding, “There’s a long way between 2 percent and 25 percent.”

Much of the hearing wrestled with the difficulty in trimming budget items that have a constituency not only on Capitol Hill — but in the case of commissaries, education and healthcare — troops.

Congressional efforts in 2016 to privatize commissaries had a powerful foe, the Senate Armed Services Committee’s No. 2 Republican, Sen. Jim Inhofe, of Oklahoma.

Even DoD’s audit has a constituency among fiscally conservative Republicans, who pushed back with Levine suggested it’s not worth the $5 billion cost when the results are apparent.

Smith noted that even the smallest proposal for savings would hit a “brick wall” because of lawmakers’ parochial concerns, citing the Base Realignment and Closure process as an example.

“People don’t want jobs lost in their districts, they don’t want things moved,” Smith said. “If we’re going to do this, we’re all going to have to find some process, bite the bullet and allow DoD to have some greater efficiency, despite the way its going to impact our districts.”