Can lawyers be blamed for the cases they accept?

Today superstar appellate lawyer Paul Clement resigned from King & Spalding after the firm withdrew as counsel representing the U.S. House of Representatives in defending the Defense of Marriage Act.  I assume that the firm feared financial blowback from taking on a case like this, much as Ropes & Gray feared being hurt on the hiring front for its decision to help Catholic Charities find a way around the Massachusetts law forbidding discrimination against same-sex couples as adoptive parents.  Though I would defend both of these representations, I reject the suggestion that lawyers are somehow beyond moral reproach for the cases and causes to which they devote themselves.  There is a moral dimension to accepting a representation.  Justifying the representation does not mean that the case or client itself has to be morally justified; there is a moral case to be made for the profession's long tradition of defending unpopular causes.  We are, and should be, morally accountable for how we spend (and don't spend) our time -- there is nothing wrong with calling lawyers out for their decisions in that regard.  (I think it's a different story entirely when a government official calls lawyers out.)  The best response to such criticisms is not to pretend that morality has nothing to do with it, thereby feeding into the lawyer-as-amoral-technician paradigm, but to offer a moral defense of the decision.