Scientists strongly lean Democratic, according to this Pew study.
http://www.people-press.org/2009/07/09/section-4-scientists-politics-and-religion/
55% of scientists are lean democrats; 6%(!) are republicans. Counting in leaners, the figure is about 81% democratic.
As such, I would expect science postgrads to have strongly supported Obama.
Some reasons for this:
a) A large proportion of scientists work in the public center
b) They are disproportionately agnostic; almost none are evangelicals (see chart at bottom).
c) Scientists of today (as opposed to say, 150 years ago) are much more interconnected throughout the globe. There is much less nationalistic rivalry as opposed to that between Germany and Britain in the early 20th century. Thus, they are strongly internationalist (and therefore do not take kindly to anti-UN rhetoric).
d) They spend longer getting degrees, therefore more time is spent in predominantly liberal postgrad cities.
e) (Much of the) Republican party's support for anti-scientific views: Support for ID/YE Creationism, scepticism/denial of global warming. When President Bush declared his support for teaching ID and evolution as "competing theories", it really showed the problems Republicans have with science. Scientists are probably less likely to vote for such a party.
