When Michael Kinsley was writing regularly for The New Republic during the first Bush administration, he was brilliant. He usually attacked Bush and made cogent arguments. I found myself agreeing with him a large % of the time. But here's how I put it to a friend after Clinton had been president for about a year: when Clinton became president, Michael Kinsley's IQ fell by about 20 points. Michael became a hack.
Of course, I don't mean that his IQ literally fell 20 points, as, I suspect, Will and Tyler don't mean their IQ claims literally. What I think we all mean is that certain biases get in the way of clear thinking. So my addition to Bryan's point is this: I would much rather someone simply judge a policy, by whatever criteria, as long as the person maintains those criteria rather than changing them depending on whether the advocate of the policy has a Rep or a Dem after his name.
So, for example, if it was evil for Bush Jr. to lock people up without a trial, it's just as evil for Obama to do so. If it's evil for Obama to extend socialized medicine to higher-income people than had previously been the case, it's just as evil for Bush Jr. to have extended socialized medicine to prescription drugs. In many of these cases, I might think that the word "evil" is over-used, but it's still better to use it generally as one's evaluation of a policy than to use it selectively depending on who is advocating or implementing the policy. I'm advocating simple consistency in making judgments, as I have long done. Our debates would be a lot better if everyone followed the standard I'm advocating.
After writing this, I went back and looked at the comments on Bryan's post more carefully. Evan had already written essentially what I said.