This doesn't exactly contradict what I was saying. Just because elected officials hold similar opinions doesn't mean economic interests can't impact their policy decisions. Also in terms of methodology, skimming through the paper, the author uses "national survey of the general public" but my claim is whether a given official reflects the will of their voters - which is not the same thing. He does also look at what "affluent" people think as some sort of proxy for the power of money. Maybe there's something there.

I think it's an interesting area of research. However on many fundamental issues, let's say illegal immigration, foreign policy, or abortions, it's not immediately obvious that business interests hold power most of the time. If that was true then it really wouldn't matter if you have democrats or republicans in power but you see definite shift in policy when that happens.