Gowdy is a DA with the mind and proclivities of a DA. He cannot function as a Senator because he is incapable of standing firm on any decision. He equivocates everything but is incapable of making a final decision about anything. As a DA he relies upon the Court and Jury to perform that function. Thus he considers himself fair minded, reserving judgement to those receiving the benefit of his remarkable investigative skills.
Mr. Gowdy is not dumb. He surely knows the Russian investigation was started under false pretenses. He surely knows that Mueller is looking for process crimes, and not collusion with the Russians, evidence of which does not exist. Any misstatement by POTUS can be used as basis for a fake crime. Surely Gowdy knows the law is not being applied equally to Democrats as well as Republicans, but he apparently overlooks that and advises Trump to imperil hiself.
Gowdy was being disingenuous in advising Trump he should talk to Mueller. He is 100% pure swamp critter.