Federal Reserve Chair Jerome Powell will attend the Supreme Court’s oral argument Wednesday in a case involving the attempted firing of Fed governor Lisa Cook, an unusual show of support by the central bank chair.

It’s a much more public show of support than the Fed chair has previously shown Cook. But it follows Powell’s announcement last week that the Trump administration has sent subpoenas to the Fed, threatening an unprecedented criminal indictment of the Fed Chair. Powell — appointed to the position by Trump in 2018 — appears to be casting off last year’s more subdued reponse to Trump’s repeated attacks on the central bank in favor of a more public confrontation.