Philosophically this is always on really shaky ground. Those that strongly support Manning's actions are saying "We want to live in a nation of laws. However, if an individual believes those laws to be unjust or unfair, based solely on his determination, then he should be free to ignore those laws and act as he sees fit. He should not be punished"
That's a pretty open ended precedent to set. There is absolutely no doubt that people die in the US every year who would not die in say a Western European country because of the choices this country makes around the role of government in helping the sick, the poor and the old. Is someone free to break the laws and put lives at risk in the name of rebelling against the injustice of those who die or suffer when we have the resources to ensure they don't?
That's why even if Bradley is right he's wrong. And btw I have so much respect for the fact he is getting 1/10th of the coverage of Snowden but may actually be more worthy if anything of attention.