LOS ANGELES — A federal judge on Friday ruled that immigration officers in Southern California can't rely solely on someone's race or the fact that they're speaking Spanish to stop and detain them.

I speak Spanish with my mother, with other relatives, with old friends. I speak it with my children, though not as often as I should. I read novels in Spanish and listen to ’80s songs in Spanish.

When I was a young UCLA constitutional law major, we learned that the Constitution wasn’t just parchment behind glass: It was a living promise, fragile and ferocious, meant to protect the people when ...