But the fact that he published secret government documents
makes him a big damn hero.

I disagree with this.

I expect government to be as transparent as possible, and not
classify documents for trivial and/or corrupt purposes (say,
because a disclosure might prove embarrassing, or politically
inconvenient).

But it doesn’t follow that everybody who discloses government
secrets is a “big damn hero.”

Manning, as best I understand it, indiscriminately dumped
whatever documents he had access to. That pretty fatally undermines
any argument that he’s a latter-day Daniel Ellsberg, nobly pulling
back the curtain on gummint malfeasance. If Manning was mistreated
while in custody, that’s deplorable, and I hope he gets justice,
but beyond that there’s every indication he’s just an unprincipled
crapweasel, and certainly not a “hero” by any standard I
recognize.