crowdpac
Crowdpac, a non-partisan firm dedicated to political data analysis, used federal campaign contribution records dating back to 1980 in order to estimate where various officials and donors fall on the political spectrum. They scored individual donors as being more liberal or conservative based on what kinds of candidates they gave to.

The company's CEO and co-founder, Steve Hilton, told Business Insider this donation data "is the heart of the Crowdpac data model" because their "research shows that campaign contributions are the best predictor of how a candidate will behave in office."

Hilton also explained that the Crowdpac's main goal is to provide people "good objective, non-partisan information about the candidates on their ballot in a simple form that they can understand." The company believes this will help "boost the number of small donors and reduce the influence of big money in politics."

As part of their analysis, Crowdpac is also able to break down where various professions fall on the political spectrum. They provided that data to Business Insider.

Here's a summary of their results:
crowdpac Donor bias summary
© Crowdpac
That basic summary shows the average ideology scores for each profession. However, the "purple" professions that appear in the middle of the spectrum aren't really bipartisan. They're actually extremely polarized: Rather than having a large number of donors with middle of the road politics, they're largely split, with a big liberal group on one side and a similarly sized large conservative group on the other.

These divides can be seen in the following charts, which were provided to Business Insider by Crowdpac and show the number of donors with each ideology score in each profession.

Liberal Professions


Some of the professional groups have clear liberal leanings. People who work in the news media are almost exclusively donors to liberal candidates:
crowdpac Media donor bias chart
© Crowdpac
Donors in the entertainment industry are similarly liberal:

crowdpac entertainment industrydonor bias chart
© Crowdpac
Academics also tend to give to liberal candidates:

crowdpac acadamic donor bias chart
© Crowdpac
The tech industry has a decidedly liberal bent as well:
crowdpac Tech companies donor bias chart
© Crowdpac
The pharmaceutical industry has some more conservative donors, but the bulk are quite liberal:
crowdpac Pharma donor bias chart
© Crowdpac
Lawyers are a bit more mixed across the spectrum, but tilt liberal:
crowdpac Legal donor bias chart
© Crowdpac
Conservative Professions

Other industries have more right-leaning donation patterns. Farmers are largely conservative:
crowdpac agriculture donor bias chart
Donors from the building and construction industries have a similar conservative lean:
crowdpac Construction Industry donor bias chart
© Crowdpac
Mining is also a conservative industry:
crowdpac Mining Industry donor bias chart
© Crowdpac
The related field of oil, gas, and coal is largely conservative too, albeit with a few more liberal donors than mining:
Oil Industry Donor Political bias Chart
© crowdpac
The tobacco industry leans to the right as well:

Tobacco Industry Donor Political bias Chart
© crowdpac
Real estate is more of a mixed bag, with a decent number of liberal donors, but a larger number of conservatives:
Real Estate Industry Donor Political bias Chart
© crowdpac
Banking and finance follows a similar pattern:

Finance Industry Donor Political bias Chart
© crowdpac
Polarized Professions

The rest of the industries reviewed by Crowdpac show a pattern of having a large number of donors from both ends of the political spectrum.

While real estate and finance had a solid conservative lean, donors from the world of hedge funds and private capital split along ideological lines, with large groups on both sides of the spectrum:
Hedge fund Donor Political bias Chart
© crowdpac
Lobbyists are, perhaps unsurprisingly considering their role in the political system, similarly split:
Lobbysts  Donor Political bias Chart
© crowdpac
Finally, automotive manufacturers and dealers also have big polarized spikes at opposite ends of the spectrum, although there are more liberals in the group than conservatives:
Auto Industry fund Donor Political bias Chart
© crowdpac