Andrew Sullivan insists upon ignoring one salient fact about the so-called bullying tactics of HRC towards King & Spalding: the attorney's client is the Federal Government. An attorney that represents the Government is acting as a Government official whether they are a Government employee or a paid contractor. Is Mr. Sullivan actually saying that Government officials should not be held accountable for their impact on public policy?
When a principled lawyer defends a guilty client, he is not through his defense saying that his client's actions were acceptable. He is rather ensuring that his client interests are protected from excessive punishment or any other unjustness in the process. In short, the lawyer is defending the person -- not the action. For this reason, it is a good thing for lawyers to represent the perpetrators of even the most heinous crimes and they should not suffer for it.
However, when a lawyer is defending the constitutionality of a law on behalf of the Government (not on behalf of some other party), the lawyer is by necessity defending the action (i.e. the law) not the person (i.e. the Government). Indeed, the lawyer is defending the law as matter of public policy. For this reason, I believe that a lawyer defending the constitutionality of an odious law does deserve scorn (and the resulting loss of reputation and business) for that defense.