This Mark Schmitt post brings up a good point. Yesterday I posted on how the defense appropriations process was heavily swayed by the $40 million spent on lobbying each year. Not that I know personally; most of that comes from reading Wastrels of Defense, by Winslow Wheeler, the former national security staffer for Pete Domenici. He's in the know, and if he's saying there's a ton of "legal corruption" going on, there probably is. (Plus, he makes a good case.)
Still, in theory it's possible that some lobbying dollars are much less insidious. In the case Schmitt mentions, Byron Dorgan (D-ND) wrote a letter requesting funds for a school desired by a Louisiana Indian tribe, and two weeks later Jack Abramoff told the tribe, a client of his, to send Dorgan $5,000 in campaign contributions. That could be corruptioni.e., Dorgan was paid to write the letterbut it might just be that Dorgan was going to write the letter anyway, seeing as how he's always done a lot of work for Native Americans, and Abramoff knew this, and so he had the tribe send some money to make it look like his lobbying efforts were worthwhile, even though Abramoff had done nothing. I guess it's inevitable that the people who hire lobbyists will be the ones getting ripped off now and again. But that doesn't mean all campaign contributions are innocent, either.