You can find many of these by clicking on this blog label: democracy.
In the Spring 2014 semester, we spent time looking through this study, and especially the following graph which points out that shifts in the opinions of the top 10% of income earners correlate with shifts in public policy, while this of the lower 90% have none:
But Andrew Sullivan flags a study that suggests that in one area of public policy, incarceration, shifts in attitudes about being "tough on crime" do correlate with the incarceration rate.
- Click here for the link.
This doesn't necessarily argue against the broader point that the opinions of the wealthy matter more for public policy, since their opinions and that of everyone else may be the same. But this does suggest that in specific areas of public policy, changes in it follow changes in public opinion - which is what democracy is supposed ot be all about.