There are lots of different studies—not as many on Canada, but lots on the U.S.—and it does vary based on discipline. Luckily, I'm in economics, and yes, there's maybe a 4:1 liberal-to-conservative ratio, but lots of people are in the centre or centre left, and people are pretty tolerant. I have good relations within my own department.
How does it work at a university? Instead of just focusing on the left-to-right ratio, think about the ratio of people who are on the far left and would self-identify as such—and I'm not talking about a liberal voter, but people who are on the far left—relative to people who are on the right or centre right. There are far more people on the far left than there are—