You are constitutionally allowed to represent yourself in a criminal case. This does not make it a good idea. Drunk driving defense in Washington, DC is a very complex area of law that requires skill at trial techniques as well as knowledge of administration of field sobriety tests, breathalyzer operation, blood testing, police procedure, and recent developments in the law. It is recommended that you hire a lawyer who specializes in this area rather than just a lawyer who will handle a DUI occasionally.