President Donald Trump has railed against Sen. Chuck Grassley (R-IA) for maintaining the customary use of blue slips in judicial nominations. Grassley, chairman of the Senate Judiciary Committee, has backed and advocated the continued use of blue slips.

Iowa, judiciary committee chairman, determines whether to allow consideration for confirmation of a federal attorney or district court judge nominee based on the approval of

Lawmakers have long abided by the practice as a mechanism for giving senators a say on judicial nominees for their home states, but blue slips have a checkered past — and critics say they are ripe for abuse.