A secret gnawed at J.W. Lown's conscience after his six years as mayor of this deeply conservative city on the West Texas plains. At 32, he began dating a young university student, and their relationship quickly grew serious. The problem? His new love was a man — and an undocumented immigrant. Advisers pleaded with the mayor to drop the romance. If word got out, it could sink his political career. Even worse, they cautioned, illegally harboring an immigrant could send him to federal prison.