Whatever your political views, this is an example to follow: Ezra Klein on Paul Krugman:
Nobel prize winner. And Krugman won it his way: He never retreated into the academy, never jealously insulated his expertise and insight from controversy because that would be safest for his reputation. Lots of folks seem to think that engagement with the public sphere puts a ceiling on academic achievement, and some had even said to me that Krugman had made himself too controversial to ever win a Nobel prize. They were wrong, and I hope more economists and assorted academics now follow Krugman's model of deploying their expertise for the benefit of an interested public.
That's a big part of what science blogging should be about.