Retired Kansas policeman Ed Hayes lives a quiet life with his wife and pet poodles in a spacious suburban home near Kansas City, far from the main front line over illegal immigration along the U.S. border with Mexico. But over the last 18 months the 66-year-old grandfather has been drawn into the battle nonetheless, becoming active on a second front. He has joined many individuals, who, with state and municipal leaders, have given up waiting for federal action and are working to control illegal immigration themselves. The issue has become a priority not only for activists like Hayes but also...