Former congresswoman Liz Cheney says a second Trump presidency would be an "existential threat" to democracy: "There's simply no defense, no excuse for putting that power back in the hands of Donald Trump." Her new memoir is Oath and Honor. Also, Terry Gross interviews Dave Davies, Fresh Air's longtime fill-in host. He's cutting back on his workload at the show. We're paying tribute to him by listening to clips of some of his memorable interviews.