The Obama administration's lawsuit against Arizona, officially unveiled on Tuesday, is an affront to all law-abiding Americans. It is a threatening salvo aimed at all local, county or state governments that dare to take control of the immigration chaos in their own backyards. And it is being driven by open-borders extremists who have dedicated their political careers to subverting homeland security policies in the name of compassion and diversity. The Justice Department's Civil Rights Division, headed by Assistant Attorney General Thomas E. Perez, took the lead in prepping the legal brief against Arizona. The son of immigrants from the Dominican...