Updated

Plenty of Republicans remain bitter that their party passed that bloated $1.3 trillion omnibus—almost as bitter as President Trump, who felt pressured to sign it. But this fight doesn’t have to be over.

Across Washington, principled conservatives are noodling with an idea that—if done right—could be a political winner. It’s a chance for Republicans to honor their promises of spending restraint and redeem themselves with a base turned off by the omnibus blowout. It’s an opening for the GOP to highlight the degree to which Democrats used the bill to hold the military hostage to their own domestic boondoggles. And it’s a chance for Mr. Trump to present himself again as an outsider, willing to use unconventional means to change Washington’s spending culture.

It’s called the 1974 Impoundment Act, which allows the president to order the rescission of specific funds, so long as Congress approves those cuts within 45 days. The act hasn’t seen a lot of use in recent decades. Barack Obama never saw a spending bill he didn’t like, and George W. Bush never sent any formal rescission proposals to Congress—likely because he took the position that presidents ought to have a fuller line-item veto power. Many conservatives agree, though Ronald Reagan used rescission where he could and holds the title for most proposals. Even so, the total amount all presidents since 1974 have put forward for rescission ($76 billion) and the amount Congress ultimately approved ($25 billion) remains pathetic.

Republicans could change that. Their control of the White House and both chambers gives them an unusual opportunity to cut big. Under the Impoundment Act, a simple majority is enough to approve presidential rescissions—no filibuster. It’s a chance to take a hacksaw to the $128 billion by which the omnibus exceeded the 2011 domestic-spending caps—everything from carbon-capture technology to pecan producers to the Gateway Tunnel Project to the Environmental Protection Agency.

Keep reading Kimberley Strassel's column in the Wall Street Journal.