I am currently studying the life of Lorca during the Spanish Civil War for a dissertation but can't seem to find much about his political stance.
He didn't have. He defined himself as "communist, catholic, anarchist, monarchist, libertarian, tradicionalist", obviously as a way to not define himself, and was a friend of personalities from both sides. Two of his brothers militated in the Falange, and after being executed, it was said from the executers it was because of his homosexuality, but he was also falsely accused of being a mason and a socialist. He wasn't aligned with a party or an ideology, defined himself as Spanish who was a brother of everyone who were good people.