Senator Sanders had been on a roll—until tonight. He had been playing a tent revival preacher in which he got himself, and his audiences of the faithful, worked up about the evil that has kept them in chains and from which he intends to free them before going on to use those same chains to whip up on the people who forged them.

“Preach it, Bernie,” his audience shouts—and Bernie preaches it. He believes and so do they. Sanders and his audience feed off each other.