Verdant Labs has created a chart comparing the occupations held by Democrats and Republicans and while some of the contrasts are obvious, others are not.

One obvious example is those that identify their profession as "Environmentalist." They are most likely Democrats. On the other hand, an "Oil Worker" would primarily lean Republican. If you are a pilot, you are more than likely a Republican. But you are probably a Democrat if you are a flight attendant.

The contrasts get more and more interesting as the branches of the various occupations broaden. One that even threw the creators for a loop fell under the category of physicians. On opposite ends of the political are urologists, overwhelmingly Republican, and pediatricians, overwhelmingly Democrat.

Occupations shown to be favored among Republicans include farming, construction, transportation, sales, and military. For Democrats, those professions include medical services, sports, academics, and arts. 

Probably the most unsurprising result was "Union Organizer," with an almost completely touching blue/Democrat circle. The highest-ranking job with the most Republicans is "Miner."

Verdant Labs explains how they created the formula and stated that because of various factors, the ratios are approximate:

This analysis is possible because the Federal Election Commission (FEC) provides data that reveals who made what contribution to which political campaign, when they contributed, how much they contributed, what they call their occupation, and other info. We aggregated that data and applied a simple formula for each occupation:

Dem % for occupation = # of people who primarily gave to Dems [divided by] # of people who primarily gave to Reps

To see the fully expandable chart, click here.