President Donald Trump's grip on federal policy could hit a serious roadblock if Republicans lose power in next month's midterm elections, and according to a new analysis from The Hill, one particular instrument stands ready to serve as Democrats' "secret weapon" in Congress for reining him in: the House Appropriations Committee.

Driven largely by voter disdain for Trump's leadership, Republicans are widely expected to lose much of their power in Washington, D.C., in the November midterms. The Senate, once viewed as safe for the GOP to retain, is becoming ever more likely to flip to Democratic control, while the House has become such a foregone conclusion that some Republican lawmakers are openly admitting that retaining their majority in the chamber is impossible.

It is in the House, according to The Hill's Sudiksha Kochi, that Democrats are poised to gain their "greatest tool" for curbing Trump's presidency. The panel writes the annual spending bills that fund federal agencies and programs, giving its chair substantial leverage over how taxpayer dollars are spent. That leverage is rooted in the Constitution, which places the power of the purse in Congress under Article I, and in the committee's structure: its 12 subcommittees draft the budgets for nearly every federal agency, from defense to the interior, while the chair sets the spending allocations that shape each bill.

"A Democratic takeover would put Rep. Rosa DeLauro (D-Conn.) in line to chair the powerful House Appropriations Committee, giving Democrats greater sway over the annual spending bills that fund federal agencies and programs," Kochi explained. "They could use the process to try to rein in President Trump's spending priorities, attach restrictions to agency funding and scrutinize how the administration is using taxpayer dollars."

She added that the strategy "could put Democrats on a collision course with the White House and congressional Republicans, particularly if they win a razor-thin House majority. Any spending legislation would still need enough Senate support to overcome the filibuster and eventually Trump's signature, limiting how far Democrats could go without Republican buy-in. Still, the appropriations process would give Democrats an opening to force the administration to the negotiating table."

Because federal agencies rely on annual appropriations to operate, missed funding deadlines raise the prospect of a government shutdown — an outcome seen in previous budget standoffs that hands whichever party controls the committee a built-in point of leverage in negotiations.

Kochi outlined several areas in which committee control would allow Democrats to subject Trump's agenda to greater scrutiny and hold his administration to account. Chief among them is Trump's use of National Parks funding to pay for his D.C. monument vanity projects. Rep. Chellie Pingree, a Maine Democrat and ranking member of the House Appropriations Subcommittee on Interior, Environment, and Related Agencies, told The Hill that Democrats plan to begin scrutinizing the practice.

"Another area Democrats will be focused on is defense funding, especially as the war with Iran has cost the U.S. billions of dollars," Kochi wrote. "Rep. Betty McCollum (D-Minn.), ranking member of the House Appropriations Subcommittee on Defense, argued that Congress needs to 'get back to parity between nondefense and defense spending.'"

She added: "For Trump, this is all a headache, particularly as he has repeatedly tested the limits of executive authority and sought to exert greater control over federal spending, challenging Congress's constitutional power of the purse."

Whether Democrats actually claim the gavel will be settled at the ballot box in November. The new Congress convenes in January, when committee leadership is organized and work begins on the next cycle of annual spending bills — the point at which the oversight tools described in the report would first become available.

The original report was published by Alternet, drawing on The Hill's analysis.