Here is what William Barr, Trump's choice for AG wrote in June:
According to the new reports about Cohen lying to congress under Trump's order, Barr would have to press charges of obstruction against Trump for suborning perjury.
https://www.vox.com/policy-and-poli...ney-general-trump-cohen-lie-congress-buzzfeedObviously, the President and any other official can commit obstruction in this classic sense of sabotaging a proceeding’s truth-finding function. Thus, for example, if a President knowingly destroys or alters evidence, suborns perjury, or induces a witness to change testimony, or commits any act deliberately impairing the integrity or availability of evidence, then he, like anyone else, commits the crime of obstruction. Indeed, the acts of obstruction alleged against Presidents Nixon and Clinton in their respective impeachments were all such “bad acts” involving the impairment of evidence. Enforcing these laws against the President in no way infringes on the President’s plenary power over law enforcement because exercising this discretion - such as his complete authority to start or stop a law enforcement proceeding -- does not involve commission of any of these inherently wrongful, subversive acts.
According to the new reports about Cohen lying to congress under Trump's order, Barr would have to press charges of obstruction against Trump for suborning perjury.