Juan Felipe Herrera, the new US poet laureate and a former California poet laureate, is a son of Mexican immigrants. He has written more than two dozen books of poetry, young-adult novels, and picture books. In his newest volume of poetry, “Notes on the Assemblage” (City Lights), Herrera reflects on the deaths of black Americans at the hands of police officers, the disappearance of 43 students in Mexico, his Mexican heritage, and the meaning of art. Herrera pivots from the political to the poignant, calling out the absurdities and sweet moments of modern life.