When President Donald Trump abruptly announced last week that he had fired Federal Reserve Governor Lisa Cook, a legendary Washington lawyer quickly stepped into the arena.

Abbe Lowell has represented New York Attorney General Letitia James, Hunter Biden, Jared Kushner, Ivanka Trump and several other high-profile political clients, both Republicans and Democrats.

Now he is at the center of Trump’s bid to expand his authority over federal regulators.

Before Trump announced he was firing Cook on Aug. 25, no American president had ever tried to unilaterally remove a Fed governor, pushing Cook and the central bank into uncharted legal territory.

But for Lowell, a fixture in Washington legal circles for decades, fighting a presidential administration’s attempt to exert control over federal regulators is nothing new.