The Biden administration has either reached, or is fast approaching, the date after which Congress can vacate rules across the federal government under the Congressional Review Act should President Joe Biden lose his reelection bid in November.

While more than 80 CRA resolutions have been introduced this Congress in an attempt to repeal executive branch actions, the few to actually make it to Biden’s desk have faced vetoes, and none of those has been overridden.

However, rules finalized this summer will likely be subject to the provision, allowing Donald Trump to quickly overturn them if he’s elected president again, as his administration did numerous times in 2017.

Trump, the presumed Republican nominee for president, has promised to cut “wasteful and job-killing regulations” and to reinstate an executive order that for every new rule finalized, two must be rescinded. At a private fundraising dinner with oil executives last month, the former president vowed to reverse dozens of environmental rules and halt implementation of new ones, according to the Washington Post.

The tool for doing so is the CRA, enacted in 1996 after being proposed by then-Speaker Newt Gingrich, R-Ga., and House Republicans as part of their “Contract with America” campaign platform. The law gives Congress the ability to overrule a regulation by passing a joint resolution, which cannot be filibustered in the Senate.

Of note for the Biden administration is the law’s “lookback” provision, which allows Congress to examine rules filed in the 60 days before Congress adjourns a session. Because of the long August recess, and another one projected for most of October because of the election, the deadline has already passed — unless Congress has to add additional legislative days to complete the appropriations process or other business.

The actual date, however, will be determined by congressional parliamentarians after Congress adjourns for the year.

Some outstanding regulations expected to arrive this summer that could be subject to the lookback period include an EPA rule governing how states and tribes administer Clean Water Act programs in which dredged material is discharged into regulated waters, and a revised lead and copper rule for drinking water systems.

An earlier date, though, could leave vulnerable certain Biden administration environmental regulations, such as the updated Corporate Average Fuel Economy standards announced June 7.

The most effective CRA resolutions have come after the White House changes party and the same party controls both chambers of Congress. The law was used for the first time in 2001 under President George W. Bush, but not again until Trump took office.

During his first months in office, Trump signed 14 resolutions reversing regulations finalized under President Barack Obama. Those included vacating part of the Interior Department’s stream protection rule and a Securities and Exchange Commission rule requiring oil, gas and mining companies to disclose payments to the U.S. or foreign governments.

While Biden and the Democrats had similar control over both chambers and the presidency in early 2021, Biden signed three such resolutions.

The CRA also prevents a future administration from finalizing any rule that is substantially the same unless directly authorized by law, and includes prohibitions on judicial review.

Rachel Weintraub, executive director of the Coalition for Sensible Safeguards, said the CRA procedures allow Congress to move quickly with little debate on resolutions disapproving of rules that “are deeply important to different constituencies.”

“I do think in a democratic process it is better to discuss these issues and better to have more conversation, especially when an agency action went through the extensive notice and comment and other procedures required by rulemaking,” Weintraub said.