The Supreme Court spent about an hour and a half on Tuesday morning arguing over whether to make it much harder for the Justice Department to prosecute hundreds of people who joined the January 6, 2021, attack on the US Capitol. It appears, after Tuesday’s arguments, that a majority of the justices will side with the insurrectionists — though it is far from clear how those justices will justify such an outcome. The case, known as Fischer v. United States, involved a federal law which provides that anyone who “obstructs, influences, or impedes any official proceeding, or attempts to do...