President Trump picked Brett Kavanaugh, a federal appeals judge with a history of challenging environmental protections, to fill the Supreme Court seat held by Justice Anthony Kennedy, the court’s longtime swing vote, who will retire at the end of the month.

The nomination of Kavanaugh sets up a fierce confirmation fight in the Senate and positions Trump to lock the nation’s top court into a dominantly conservative posture on dozens of issues, including climate change, for decades to come.

Trump revealed his nominee last night at a White House ceremony in the East Room, where Kavanaugh, with his wife and daughters by his side, promised to be an independent jurist unaffected by the political turbulence surrounding him.

“If confirmed by the Senate, I will keep an open mind in every case,” Kavanaugh said, reading from prepared remarks.

The departure of Kennedy, who cast the deciding fifth vote in the landmark Massachusetts v. EPA climate change lawsuit in 2007, creates an opportunity for a more conservative court to dilute or even overturn climate rules. That case laid the legal groundwork for federal action to reduce greenhouse gas emissions. With Kennedy gone, Chief Justice John Roberts becomes the swing vote and a bridge to the court’s liberal bloc.

Environmental advocates are promising to fight Kavanaugh’s nomination, but there is little they can do to stop his confirmation. Several environmental lawyers, when reached for this story, groaned when asked about the climate implications of a court without Kennedy.

“Some people have said it could nudge the court to the right,” said Glenn Sugameli, founder of Judging the Environment, which analyzes judicial nominees. “It’s way worse than that.”

Since 2006, Kavanaugh has served on the U.S. Court of Appeals for the District of Columbia Circuit. From that perch, he has bristled against EPA regulations. That tendency reflects his stringent views related to an agency’s responsibilities when creating rules, rather than a reflex against environmental regulations, some experts said.

“He really checks the homework of regulatory agencies,” said Jonathan Adler, director of Case Western Reserve University’s Center for Business Law and Regulation.