JERICHOW, Germany – On a warm afternoon in the small east German town of Jerichow, Ulrich Siegmund looked less like a political firebrand and more like a polite neighbour.Slender, with neatly parted hair, and wearing an approachable smile, the 35-year-old moved easily across the central square.He shook every hand and patted dozens of backs. He asked about family, remembered names and patiently posed for smartphone wefies with anyone who asked.By the time the town’s “AfD Barbecue” reached its peak, more than 300 locals had gathered under the blue-and-white banners of the Alternative fur Deutschland (AfD). They ate grilled sausages, drank...