Indeed, a recent study done at Princeton and Northwestern Universities looked at 1,800 laws enacted between 1981 and 2002 and compared them to the interests of average Americans (in the 50th percentile) and the interests of the rich (90th percentile) and special interest groups. To little surprise, they found that the interests of average Americans are almost completely ignored. In the words of the study:
When a majority of citizens disagrees with economic elites and/or with organized interests, they generally lose. Moreover, because of the strong status quo bias built into the US political system, even when fairly large majorities of Americans favour policy change, they generally do not get it.
The few times that average Americans do get laws passed to their benefit, it is only because the rich also win.