(CNN)Liberals have to avoid Trump Derangement Syndrome. If Trump pursues a policy, it cannot axiomatically be wrong, evil and dangerous. In my case, I have been pretty tough on Trump. I attacked almost every policy he proposed during the campaign. Just before the election, I called him a "cancer on American democracy" and urged voters to reject him. But they didn't. He is now president. I believe that my job is to evaluate his policies impartially and explain why, in my view, they are wise or not.