SANDY, Ore. — Trucks carrying bales of hay, horse paddocks and Christmas tree farms — drive a few miles out of Portland and the suburbs quickly give way to rural Oregon. Barely a half-hour from the Portland streets where racial justice protesters on Saturday were marking 100 consecutive days of tempestuous, sometimes violent, demonstrations, there are plenty of communities where people dismiss the protesters as lawless hooligans. “Portland is an island in Oregon,” said Stan Pulliam, the mayor of Sandy, a more conservative town of 10,000 people about 30 miles southeast of Portland that feeds off the economic dynamism of...