On Nov. 1, 2006, I found my wife, Adrienne Shelly, dead in her West Village office. Adrienne, an actor and filmmaker, had been brutally murdered by a 19-year-old undocumented Ecuadorean construction worker; he later said they were having an argument and, fearing she would report him and have him deported, he killed her and staged her death so it would appear to be a suicide. Our daughter was just 2 years old at the time. Given the anger and grief I still feel, I could easily be seduced by Donald J. Trump’s anti-immigrant rhetoric that is the cornerstone of his...