I think it is less likely for scientists and engineers to be liberal, just because those disciplines require one to be rational. The far left snowflake who goes into a tizzy screaming about how the STEM fields discriminate against women would never actually study a STEM field as it is way above their intellectual capacity.
The majority of science and engineering departments are very liberal. Look at the voting patterns of towns filled with scientists and engineers. Look at Silicon Valley, look at where scientists and engineers live around Boston. Those towns are overwhelmingly liberal. The ‘elite’ professors really do think they know more than the average citizen.
What is different about the scientists and engineers is they are much less likely to fill their courses with propaganda the way some liberal arts and gender studies departments do. But when they go to the voting booth they are liberal.
Liberalism permeates every department - even in the sciences. Here is an example of a liberal physicist denouncing white male science. LOL
http://www.freerepublic.com/focus/f-news/3577363/posts