Arizona’s crudely drafted and unconstitutional immigration law, already battered in its journey through the federal courts, had yet another setback today. A three-judge panel of the United States Court of Appeals for the Ninth Circuit, in San Francisco, ruled that its provisions forbidding day laborers to look for work violate the First Amendment. You may remember that the law, SB1070, signed by Gov. Jan Brewer in 2010, was a grab bag of enforcement measures meant to provoke a mass exodus of undocumented immigrants, which Arizona Republicans, including Ms. Brewer, have routinely depicted as a terrifying horde of narco bosses, mules, gangbangers and terrorist assassins sing over the border. SB1070 was an invitation to harassment, false arrests, racial profiling and other abuses of Arizona’s immigrant and Latino population (and people who happen to look Latino).