The ABA's theme for Law Day, May 1, is representing unpopular causes.  This article by Ed Finkel in ABA Journal notes that theme features John Adams and his defense of the British soldiers tried for murder after the Boston Massacre.  Adams got acquittals for six and got two off with manslaughter rather than murder.  Under the odd and soon-to-be-scrapped sentencing law of the time, that meant the difference between light punishment and hanging.  See G. Dalzell, Benefit of Clergy in America 204 (1955).  (For a brief summary of this early sentencing law, see Part I of our brief in Ring v. Arizona.)

The article's dateline says it was posted May 1, 2011, but unless I have stumbled into a time warp that is not correct.

Representation of detainees at Guantanamo Bay is mentioned as the modern equivalent of Adams' stand.  The DOMA kerfuffle is not mentioned.