I'm not sure that I can completely agree with this. The election of 2010 saw a very large number of "turn-overs" in both federal Congressional seats and state Legislative seats. While I can't speak to EVERY race around the country, the ones that I took an active interest in were in no way influenced by corporate interests. Those new politicians were listening mostly to the people at the Tea Party rallies and other local town hall situations.
It was people who disrupted an AARP meeting (in Texas I think) about the health care issue to the point that the AARP people just folded up and left. The people stayed and had an impromptu discussion about the legislation after the AARP people were gone.
Also, I think I remember reading somewhere that people were donating more towards individual candidate's campaigns than towards political party campaigns. While I am sure that corporations were still donating to the parties, I don't really think they had that much of an influence on the way the electorate voted.
Well, maybe there is still hope.