Tañada is described to be a "person who metamorphosed from a graftbuster to a nationalist and... a crusader of various causes." Apart from being characterized as an esteemed nationalist, Tañada was also regarded as the leader of the "parliament of the streets". He had an infallible stance against graft and corruption, inequality, and tyranny. He was also the chief prosecutor against Japanese collaborators. Because of his political reputation, Tañada became a Filipino praised by all of Philippine society, a person honored by both the Communist Party of the Philippines and the Reform the Armed Forces Movement, and a man who was acknowledged as a man of principles even by Benigno Aquino, Sr., grandfather of Pres. Benigno "Noynoy" Aquino, who Tañada himself once charged as a "collaborator". He was one of the petitioners in the landmark Supreme Court case "Tañada vs. Tuvera", which declared that unpublished laws (a characteristic of the Presidential Decrees of Marcos) are without effect.