Written on Monday, teased with a snippet on Instagram that same day, and then released in full on Friday, Lana Del Rey’s “Looking for America” is a rapid-response protest song — following a slew of mass shootings — from an artist whose tortured relationship to an idealized America has always been central to her persona. “Pulled over to watch the children in the park/We used to only worry for them after dark,” she sings, lightly vibrating with anger. What makes this protest so striking is that Del Rey sings about the country’s fall from grace (“I’m still looking for my own version of America/One without the gun, where the flag can freely fly”) with a convincing wistfulness, the sort that jingoists think is all their own. JON CARAMANICA