After winning both of Georgias runoff Senate races and taking back the Senate after six long years, Democrats have a window of opportunity to undo some of President Donald Trumps anti-regulation legacy.

The Trump administration has weakened workforce safety standards, gutted pollution rules, promoted junk health insurance, and rolled back rules on everything from drilling in the Arctic to protections for transgender persons in homeless shelters. On the campaign trail, President-elect Joe Biden promised to reverse at least 100 Trump-era rules.

The Congressional Review Act is a 1996 law that gives Congress the power to nullify any major regulations an executive branch agency finalized within the previous 60 days, not counting periods when Congress was out of session for three days or longer. Republicans used the act, known as the CRA, to hack away at Obama-era rules; before that it had only been used once, in 2001.

I have no doubt that we will aggressively move forward to undo as many of the damaging environmental rules and executive orders as were capable of undoing, Sen. Brian Schatz (D-Hawaii) told HuffPost on Wednesday.

Crucially, the CRA requires only a simple majority of senators to get a disapproval resolution through the Senate. Thats good for Democrats, who will only control 50 seats in the Senate and have to rely on Vice President-elect Kamala Harris for tie-breaking votes.

Republicans made extensive use of the CRA in the early days of the Trump administration, after learning of a convenient loophole that let them review regulations and guidance that had been on the books for decades as long as they hadnt technically been submitted to Congress yet. They nixed 16 regulations, including one that had been finalized in 2013 .

According to the Regulatory Studies Center at George Washington University, the new Congress could use the law to kill any Trump regulations that were published in the federal register on or after Aug. 22, 2020 .

The CRA also makes it harder to revive those rules, prohibiting agencies from reissuing regulations that are substantially the same as ones stricken by the law.

A Toxic Legacy

Climate and environmental rules have been perhaps the biggest target of Trumps deregulatory agenda. Since taking office, the industry-friendly administration has scrapped, weakened or proposed rolling back nearly 100 environmental rules and regulations, according to a New York Times analysis .