I’m not American, it just happens that where I live everyone is quoting from Gramsci’s cultural hegemony at the moment. ^^

My point is you don’t need to leak to matter, or do anything illegal. The simple fact that powerful institutions are staffed with people who share your ideology is helpful to you. (I do have a lot of respect for leakers though)

If all people who share your opinions think like you then that institution will be left to your opponents.

Joining would be praxis. You don’t have to be a double agent or anything, just be a sympathetic voice in meetings and such. Simply making the institution politically diverse and preventing it from being an echo chamber of like-minded people is already making a change in the world.

As an example, in 1923 Hitler attempted a coup, but got off with an amazingly light eight months of prison. The reason is the judiciary at the time were quite sympathetic to him; they didn’t do anything illegal, yet had they been SPD supporters instead Hitler might have gotten a life sentence for his high treason.