Democrats' Senate win may deliver the strongest check yet on Trump's push to reshape the Fed. Until now, checks on the longstanding institutional relationship ("Fed independence") have been piecemeal: Tillis's blockade, Powell staying on as a governor, and court rulings that kept Lisa Cook in her seat for now.

Trump got his new chairman, Kevin Warsh, this spring, but a majority of the Fed board was appointed by other presidents. There are no vacancies and should there be any, a future nominee would need to win confirmation by a Democratic Senate.

That raises a question: Does the Venn diagram of "Fed pick who can satisfy Democrats' independence concerns" and "nominee acceptable to Trump" have any overlap? No Democrat voted in favor of Stephen Miran's confirmation or for Miki Bowman's promotion to vice chair for bank supervision last year. Warsh won just one Democratic vote, from Fetterman.