 He soon stood out as a student leader supporting the working class.He participated in protests against the regime of Augusto B. Leguía, standing out as a vigorous and eloquent speaker, with great power of persuasion due to the depth of his ideas.Banished by Leguía in 1922, he emigrated to Mexico, where in 1924 he founded the American Popular Revolutionary Alliance, a political movement with continental projection and a social democratic orientation, initially with a clear anti-imperialist position.