Rep. Jared Huffman, who represents Marin County and the North Coast, may be among the most unusual members of the House — and the only one who will say out loud that he doesn’t believe in God. In his new book, “No Prophets,” he argues that Christian nationalism has given up on democracy. He explains why he thinks the Jan. 6 attack on the Capitol was a religious event, and what it means when a movement decides it no longer needs to win elections.