President Donald Trump threatened legal action over a Senate tradition Democrats have used to block certain judicial nominees, escalating a long-running dispute with Senate Judiciary Committee Chairman Chuck Grassley (R-IA).

The Judiciary Committee chair, and his fellow Republicans, have so far brushed off pressure from the president to nix the long-standing practice.

Iowa, has previously rejected President Donald Trump’s calls to disregard the federal official confirmation tradition. The senator’s spokesperson quoted him as telling