Climate scientists have received threatening letters and e-mails for years. Their names have been dragged through the mud in congressional hearings, on newspaper editorial pages, on talk-radio shows, and in their home communities by those seeking to distract and mislead the public. Despite the continued harassment, however, scientists were still winning in the court of public opinion. The majority of the public understood that the overwhelming body of evidence supports the theory that the earth is warming and that humans are contributing significantly to the warming. Scientists and the organizations that represent them had made significant headway in helping the public and policy makers better understand what is happening and what can be done to mitigate and adapt to changes in the earth's climate. In this article, the author argues that when scientists are attacked professionally and personally, independent science and the public suffer. He discusses how ideological attacks on scientists undermine sound public policy.