Plutocratic bribery of Congress has become highly sophisticated; bags of money are virtually unheard of. It often occurs by verbal promise so that the giving and receiving are separated by both time and form of the bribe (e.g., favorable legislation now, highly paid lobbyist later; election support now, favorable legislation later; etc., etc.). Trust is enforced by acknowledged but informal organizations and groups; failure to perform is vigorously punished by members of those organizations.
Our Founders' Warning: “Every government degenerates when trusted to the rulers of the people alone. The people themselves are its only safe depositories.” (Thomas Jefferson)