There’s plenty of talk about a ‘Constitutional crisis’ if President Trump does or doesn’t do this or that. But most of those scenarios are utter nonsense, because many of the things discussed are clearly Constitutional and quite well-defined, in that the President has a specific power, or that he is not subject to a specific demand by Mule-head.
My view is that a Constitutional crisis will occur when Trump declassifies and orders Rosenstein, the DOJ and the FBI to turn over the documents, and they refuse. And I really believe that the will refuse, with a B.S. excuse that they are patriots who are protecting the country.
What they are protecting is themselves, Obama, Hillary and a host of others.
What you describe isn't a "Constitutional crisis". The Constitution has an easy remedy if Rosenstein doesn't turn over the documents. The president can fire his subordinate.
Occam’s Razor: Trump is satisfied with the job Rosenstein is doing. He’s not the one complaining. Trump can have that information released by making a phone call. Congress is the one doing the yelping.
For those who keep insisting “obstruction!” is why Trump won’t fire Rosenstein or Sessions- those two are administrators, they aren’t running investigations. The 1926 SCOTUS decision Myers v United States gives presidents the unrestricted authority to fire executive branch officials. Congress can’t impeach him for exercising a power that is solely his.