They say a man who represents himself has a fool for a client. Well, with God as my witness, I am that fool! –Gomez Addams, The Addams Family.
Aside from Gomez, anyone, even a skilled lawyer who handles their own case is at a disadvantage. It is very difficult to assure that reason, rather than emotion, dictates the proper strategic response to developments in the courtroom.
However, the right to represent yourself in court and refuse the assistance of a lawyer is a constitutional right. A Manhattan judge denied requests by a defendant to proceed without an attorney without any inquiry at all. The case was appealed and the appeals court ordered a new trial.
The decision is found at the following link: http://www.courts.state.ny.us/reporter/3dseries/2014/2014_00592.htm