Pvt Bradley Manning acted to expose improprieties committed by the he US government. He was acting to inform WE THE PEOPLE, the true foundation of the United States. The Federal bureaucrats military may have found him to cause THEM harm by exposing what the government was/is doing, but he is really a whistleblower.
Manning should be pardoned as his actions were without malice and done in the interests of the People, and not the administration.