Adeel Mangi, the first Muslim nominated for a federal appellate court judgeship, withdrew his nomination for the U.S. Court of Appeals for the 3rd Circuit in a fiery letter to President Joe Biden on Monday, accusing senators of engaging in a smear campaign that tanked his chances.

“This is no longer a system for evaluating fitness for judicial office,” Mangi wrote, describing the judicial confirmation process as driven by “performative McCarthyism” and “dark-money-funded attacks that especially target minorities.”