At a Saturday-evening fundraiser held in the home of a wealthy Massachusetts hospital executive, President Obama suggested Democrats are having difficulties in midterm campaigning because Americans simply aren't thinking clearly. Seeking to explain his party's troubles, the president focused not on controversial legislation like national health care and the stimulus but on evolutionary psychology. "Part of the reason that our politics seems so tough right now, and facts and science and argument do not seem to be winning the day all the time, is because we're hard-wired not to always think clearly when we're scared," Obama told the assembled Democrats,...