Via Sean Carroll, Nature (yes, Nature!) endorses Obama (via Sean Carroll):
[S]cience is bound by, and committed to, a set of normative values — values that have application to political questions. Placing a disinterested view of the world as it is ahead of our views of how it should be; recognizing that ideas should be tested in as systematic a way as possible; appreciating that there are experts whose views and criticisms need to be taken seriously: these are all attributes of good science that can be usefully applied when making decisions about the world of which science is but a part. Writ larger, the core values of science are those of open debate within a free society that have come down to us from the Enlightenment in many forms, not the least of which is the constitution of the United States.
On a range of topics, science included, Obama has surrounded himself with a wider and more able cadre of advisers than McCain. This is not a panacea. Some of the policies Obama supports — continued subsidies for corn ethanol, for example — seem misguided. The advice of experts is all the more valuable when it is diverse: ‘groupthink’ is a problem in any job. Obama seems to understands this. He tends to seek a range of opinions and analyses to ensure that his own opinion, when reached, has been well considered and exposed to alternatives. He also exhibits pragmatism — for example in his proposals for health-care reform — that suggests a keen sense for the tests reality can bring to bear on policy.