You can't be an ethically-minded person and do what Manning did. Nor can you apologize or justify it; it was just plain wrong. He didn't release them because he had some great concern for some great evil being perpetuated; he released them because he was disgruntled or had some anti-American feeling that took hold. He didnt have any knolwege that anything wrong was going on, or else I'm sure he would've released the damning documents themselves (which don't exist), rather than entire databases full of classified information. There are channels in place for whistleblowers to expose misconduct in the military, including classified channels which do not reveal our secrets to adversaries.
Regardless, releasing classified documents jeopardizes the mission by revealing our tactics, sources, future operations, the extent of our intelligence, our capabilities, etc. I guess if you think it's cool to put US military operations at risk, or put Coalition lives at greater risk, you can turn Manning into a folk hero. You'd have to hold a sincere belief that al Qaeda and the Taliban remnant are morally superior to US/NATO forces to do so, however.
As for the political side of your argument, I could not be less interested in discussing it with you. I'm neither Democrat nor Republican, and it's foolish to think that misconduct occurs on just one side of the aisle.