For two decades, President Recep Tayyip Erdogan has loomed large over Turkish politics. But skyrocketing inflation and a devastating earthquake have eroded his power and, in a presidential election over the weekend, he was forced into a runoff. Ben Hubbard, The Times’s Istanbul bureau chief, discusses how Turkey’s troubles have made Mr. Erdogan politically vulnerable. Guest: Ben Hubbard, the Istanbul bureau chief for The New York Times.