EDITORIAL: Congressional Review Act gives GOP a rare opportunity to undo Obama mandates.

Republicans have already used the Congressional Review Act to undermine President Barack Obama’s record-setting regulatory barrage by repealing a handful of the former administration’s last-minute edicts. And now it appears the law will help the GOP venture much deeper into the regulatory thicket.

The act dates back two decades to the 1994 Contract with America, which outlined a limited-government, market-oriented agenda that helped Republicans gain control of the U.S. House for the first time in more than 40 years. The measure created a 60-day window during which the House and Senate could overturn any new executive branch rules as long as the president didn’t veto the action.

In the past 23 years, the act had been used only once. But with the GOP controlling Congress and a Republican replacing a Democrat in the White House, the stars are now aligned.

Todd Gaziano, a senior fellow in constitutional law at the Pacific Legal Foundation, points out that the Congressional Review Act actually gives Republicans power to roll back not only rules rolled within the past 60 days, but also regulations dating back to the beginning of the Obama administration.

As the Wall Street Journal’s Kimberley Strassel outlined in a January column, the act requires federal agencies putting new rules into effect to submit a report on the regulations to both the House and Senate. The 60-day clock starts ticking when the rule is published or when Congress receives the report — whichever comes later.

“There was always intended to be consequences if agencies didn’t deliver these reports,” Mr. Gaziano told the Journal. “And while some Obama agencies may have been better at sending reports, others, through incompetence or spite, likely didn’t.”

In other words, Obama agencies never filed the requisite reports for a number of regulations. That means the Trump administration could go ahead and submit those notices, triggering the 60-day clock for Congress to act. Ms. Strassel explains that once Congress rejects a regulation, it can never be resubmitted in a substantially similar way, effectively killing it for good.

Would the Democrats push back? Sure. But Ms. Strassel correctly argues that it’s a fight worth having. “Democrats certainly would show no such restraint were the situation reversed,” she adds. “Witness their treatment of Mr. Trump’s Cabinet nominees.”

This is a prime opportunity for the new president and Congress to chip away at the bloated regulatory apparatus. While some federal rules certainly serve a useful purpose when it comes to protecting consumers, many others create unnecessary red tape and hinder growth. Republicans in the House and Senate should give the Congressional Review Act a thorough workout.