House Judiciary Committee Chairman Jerrold Nadler accused Senate Republicans of violating their oath to be impartial jurors in an impeachment trial, as GOP senators defended their right to work for President Trump’s acquittal. Senators take an oath to “do impartial justice” at the start of any impeachment trial — but several Republican senators argued that impartiality doesn’t cover politics.

The Utah lawmaker Orrin Hatch, who sits on the Senate Judiciary Committee, filed a 44-page amicus brief earlier this month in Gamble v. United States, a case that will consider whether the dual-sovereignty doctrine should be put to rest. The 150-year-old exception to the Fifth Amendment’s double-jeopardy clause allows state and federal courts to prosecute the same person for the same criminal offense.