Lorca was probably the most cited Spanish-language poet in the context of U.S. poetry from the late 1930s until Neruda's Nobel prize in 1973, but since then Neruda is clearly the most popular. Just browse the best sellers at Amazon under Literature and Fiction / Poetry / Spanish and you will see that Neruda occupies the spots of 1, 3, 6, 7, 9, 11, 12, 13, 15, 18, 19 21, 23, 25, 29, 31, etc... (For yesterday, anyway). No other poet even comes close. The other top sellers are not Vallejo or Lorca, Jiménez or Machado, but what appear to be children's books like Tortillas para Mamá and Arroz con leche. (I'm actually pleased that people seem to be reading poetry in Spanish to their children.) ( #19 is Bly's Neruda and Vallejo, which is still in print after all these years. The top rated Lorca book is at #42.)