The United States Constitution forbids individual states from preventing qualified attorneys from practicing law based on the lawyer’s political leanings. Massachusetts violated the Constitution by including a question on homosexual marriage on the Massachusetts bar examination.You're missing the point, Mr. Dunne - the Bar exam is a test to see if you have a sufficient grasp of what the law is, not what you want it to be. If I answered a Bar exam question on a search & seizure issue based on how I'd interpret the Fourth Amendment, rather than how the Supreme Court actually has done so, I'd bomb out on that question. Coincidentally, if I go to the Fourth Circuit and try to tell the court what the Fourth Amendment really means, versus what they've said it means, I lose. Big time.
No state can refuse the granting of a law license based upon one’s particular viewpoint.
You obviously have a problem with gay marriage, either in concept or in how it was implemented in Massachusetts. Fair enough. But if want to practice law in that state, you need to know what the Supreme Judicial Court says that law actually is. Suck it up, answer the question, and pass the test. Then you can advocate for a change in the law as an attorney.
As for the idea that a state can't deny someone Bar membership because of their beliefs, ask Matt Hale, although that's obviously an extreme case.
UPDATE: Mr. Dunne has a website dedicated to his lawsuit here, which I discovered via his comment to this post here.