up to the supreme court. so this could be a very big battle that could go on over mo another cloud hanging over this , in addition to this investigation, this question about whether or not the president will even sit down for an interview with mueller. >> and i noted tt rudy giuliani slipped in the mention of a posble subpoena with laura ingraham who is herself a very good lawyer. nelson, you're nodding yes. >> last month i sat down and took a look at the legal precedent and wrote a piece for politico. the supreme court cases leave very little doubt that the president must comply with a criminal subpoena. in u.s. versus nixon, the watergate precedent, the supreme court said richard news at 6:00 son had to provide documents in response to a criminal subpoena from the grand jury in washington, d.c. he had no ability to avoid that.