The biggest single factor driving American academe to the political Left was the Vietnam War. Draft dodgers (uniformly Left-leaning) ALL went to college, and found the academic environment soft and cozy, and they remained in school as long as possible in order to retain their draft deferments. Over time, they moved up, gaining professorships and department chairs, eventually driving out anyone not ideologically similar. Hence we have no more than a smattering of professors in the entire country who are - I won't even say Conservative or Libertarian - NOT extreme left-wingers of one sort or another.
The starting salary information above has to be taken with a grain of salt. The majority of students at these institutions are upper middle-class and well-connected even before they go to college, and are hard-wired into good, fast-track positions, regardless of what college they would choose to attend.
P.S. Engineering is a very dubious career choice, even though it often carries the highest starting salaries for new graduates. Career advancement for pure engineers is very limited. There are perpetual complaints that each year's new grads are getting as much as engineers who have been with the Company for years. The best options, financially, for engineers are technical sales, project management, or law. Sorry to say.
