The official channel is Congressional oversight committees for intelligence. They all have clearances and are independent of the executive branch and the agenci

The official channel is Congressional oversight committees for intelligence. They all have clearances and are independent of the executive branch and the agencies they oversee. The extent to which you trust them is up in the air, I guess, but they're at least supposed to be representatives of the public. It's more like the city council investigating the police than the police investigating themselves. As for what would have changed, what changed given he publicly disclosed instead? As far as I know, none of the programs he blew a whistle on were ever found to be illegal, no one in charge of them was fired or went to prison, and the major effects have been crackdowns in the way insider threats are mitigated, the depth that clearance investigations and polygraphs go into, the public has become less trusting of the federal government, and backers of authoritarian foreign regimes have a lot more ammunition to paint the USA as full of hypocrites if we ever take any effort to aid resistance to them.