Billionaire investor Carl Icahn has created a new political action committee, and if you’re looking for an example of the ways deep-pocketed donors skew the U.S. policy agenda, this one’s a doozy. The PAC’s main focus is pushing for lower taxes on the overseas operations of American corporations.

There’s a huge divide between average voters and people who make big donations to political campaigns. It shows up not just with famous, rich people like Icahn but also in donations made by the merely affluent. In a 2011 paper for Political Behavior, Brittany H. Bramlett, James G. Gimpel, and Frances E. Lee considered the issue in geographical terms, looking at the places where campaign donors live.

The authors write that people living in only 5 percent of the nation’s zip codes—mainly around large metro areas—accounted for 67 to 77 percent of itemized campaign donations during political cycles from 1999 to 2006. For the paper, they look at surveys of political opinion for these neighborhoods. Then, they compare the results with nationwide results, and also with opinions of people living in the 5 percent of zip codes with the fewest donors.

Their analysis shows that, while residents of high-donor areas aren’t monolithically Democratic or Republican, they have a much stronger tendency to favor policies that the researchers characterize as cosmopolitan. Only 48 percent of them say foreign competition is a problem, compared with 68 percent of average voters, and 79 percent of residents in neighborhoods with the fewest donors. They’re also much more likely to favor free trade deals and to say illegal immigrants should be able to become citizens. Meanwhile, on social issues, people in the areas with lots of donors strongly oppose banning abortion (80 percent versus 66 percent for all Americans and 57 for low-donor neighborhoods). They’re also much more likely to support same-sex marriage and more gun control.

“Respondents in high-donor neighborhoods stand opposed to the populist causes of both the left and the right,” the authors conclude.

Of course, it makes sense that typical big campaign donors are different from everyone else in the country in a lot of ways—most notably, being pretty wealthy. But Bramlett, Gimpel, and Lee found that individual characteristics alone couldn’t explain the different political positions they found in donor-rich areas. Even after controlling for income, race, church attendance, left-right ideology, and other individual-level variables, they found significant differences in policy positions between these places and other parts of the country.

The authors suggest this reflects the way that people’s environments influence their understanding of the world.

“Donor neighborhoods embed their residents in an environment that socializes them and links them together in ways that skew opinion away from the national mainstream,” they write.

In other words, the wealthy neighborhoods where most campaign donors live are their own little worlds, in which cosmopolitan attitudes that are controversial in other parts of the country may just appear as common sense.