Senate Democrats began using a special procedure to undo parts of Donald Trump’s regulatory agenda Wednesday, starting by rescinding a measure that made it harder for the Environmental Protection Agency to limit leaks of the powerful greenhouse gas methane from oil and gas wells.

The 52-42 vote on the methane rule is the first of several that Democrats plan to use under the Congressional Review Act. That 1996 law allows lawmakers to rescind federal regulations passed in the waning days of a presidential administration as long as they act within a few months of a new Congress.

It had been used only once before 2017 when Republicans, led by then-President Donald Trump, used it to repeal 14 Obama-era rules including one that limited the ability of the mentally ill to buy firearms to another forcing oil companies to disclose their payments to foreign governments.

“The Congressional Review Act was seen as this very extreme thing. It was almost like an atomic bomb. It wasn’t something you just casually trotted out,” said James Goodwin, a senior policy analyst the Center for Progressive Reform, a Washington-based non-profit. The Trump administration and the 115th Congress “normalized it in this way it hadn’t been previously.”