Until today, I have defended Mueller against the accusations that he is a partisan. I did not believe that he personally favored either the Democrats or the Republicans, or had a point of view on whether President Trump should be impeached. But I have now changed my mind. By putting his thumb, indeed his elbow, on the scale of justice in favor of impeachment based on obstruction of justice, Mueller has revealed his partisan bias. He also has distorted the critical role of a prosecutor in our justice system.

Virtually everybody agrees that, in the normal case, a prosecutor should never go beyond publicly disclosing that there is insufficient evidence to indict. No responsible prosecutor should ever suggest that the subject of his investigation might indeed be guilty even if there was insufficient evidence or other reasons not to indict. Supporters of Mueller will argue that this is not an ordinary case, that he is not an ordinary prosecutor, and that President Trump is not an ordinary subject of an investigation. They are wrong. The rules should not be any different.