Adam Bonica, a grad student in political science at NYU, recently published a ranking of the political slant of various professions, based on the amount and recipient (Republican or Democratic) of political donations by lawyers, lobbyists, physicians and many other occupations. This paper (PDF) gives the complete analysis, but the chart below (created using the ggplot2 graphics package in R) sums up the results nicely (click to enlarge):
(I liked this quote from Paul Kedrosky about this chart: "How come gas station attendants are so damn partisan?") Now, Adam has taken the analysis to the next level, by looking at employees of individual companies, instead of professions as a whole.
(Unfortunately, it's not entirely clear if the data point lies to the left or at the middle of the company label; this table helps sort out the exact rankings.) It may not be a surprise, for example, that Google's employees tend to give to Democratic-leaning candidates, but does that influence Google's policies as a whole? Adam's article at the link below delves into this question in more detail.
Ideological Cartography: The University of Google: Was the decision to exit China ideological or business as usual?