A few weeks ago, I visited the fence that made Hungary a symbol of European anxiety. Chain-link and razor wire, it slices through pastures as it traces Hungary’s southern border. More than 100 miles long, it was constructed quickly this summer as refugees streamed into the country, heading toward Austria and Germany. Police officers and soldiers were stationed every few hundred yards, and they examined my passport at almost every checkpoint. They seemed bored, perhaps because the flood of refugees and migrants had mostly abated. The fence had sealed Hungary off, and that made Laszlo Toroczkai — the 37-year-old mayor of Asotthalom, a Hungarian farming town on the Serbian border, and a rising ultranationalist star of far-right European politics — very happy.