Almost every US lawmaker takes big money aimed at helping private interests win favorable government action. If they stash the cash for themselves, it's illegal. If they use it to get reelected, keep their job, and help the private interests, it's generally legal.
Either way, money still talks in Washington and the legal/illegal distinction gets easily blurred in all the backroom dealings with private interests until, that is, a brazen case of bribery pops up. Then Washington, if it had any sense, might ask if the laws and rules that regulate campaign donations and lobbyist gifts are tough enough or prosecutors are vigilant enough.
Obviously the laws and prosecutors weren't good enough in the case of Randy "Duke" Cunningham. The California Republican congressmen resigned on Monday after admitting he took $2.4 million in bribes - yes, $2.4 million - to help steer Pentagon business toward select defense contractors. (Newspapers, not prosecutors, first exposed Mr. Cunningham's unexplained wealth.)
Strangely, his official crimes were committed openly in Congress as he worked like many lawmakers in pushing through specific benefits for private interests or calling government departments to coerce a decision in favor of a well-funded, private interest. The plea agreement stated he steered spending "to the benefit" of defense contractors who bribed him, and those contracts were not "in the best interests of the country."