Er, no. A case for that assertion could be made if Buchanan had a record of defending a wide variety of people accused of crimes. His actual record is, shall we say, more selective.
His years long efforts on behalf of Karl Linnas commander of the camp at Tartu, Estonia was more revealing. He pressured Ed Meese for years to drop his deportation, then pushed for some country to grant him entry. Eventually Meese had no choice but to follow the law and deport him.