John Adams, our second President, first came to prominence when he defended English soldiers accused of murder in the Boston Massacre. Defense lawyers have always represented unpopular defendants. Judy Clarke, who defends Dzhokar Tsarnaev in the Boston marathon bombing case, is another fine example. A defense lawyer need not love the client or the client’s conduct; but that lawyer can never harm the client’s interests. In the recent case of a South Carolina police officer accused of murdering an unarmed man, some critics believe that is exactly what the officer’s former attorney did.