badbadhusky, I wouldn't suggest that reshaping the constitution is something the Bannonites/Mercerites are specifically engineering.
More that Bannon is very public about wanting to break as many things as possible - in the hope things will fall in his mob's favour. Which they very likely will, because if you're extremely rich and powerful you're in a better position to benefit from disaster opportunism, and to use the disruption to remove any regulations which redistribute power away from the ultra-rich, ultra-connected to the ordinary people.
So my guess is they may not have knowingly engineered it, but they wouldn't be upset if one of the things that got broken was the constitution.
Bannon's behaviour has several times reminded me of a bit in War and Peace during the Battle of Borodino, when General Kutuzov doesn't give orders but simply acknowledges the decisions his front line commanders have made. Come the victory, he's given credit for the lot.
In Kutuzov's case, this is described as the actions of a good general who has put in the groundwork for his army. But I see Bannon doing it opportunistically. Whether a disruption is of his initiating (the Muslim ban followed by the airport protests), or directly harms him (him being fired) he simply claims the whole shebang is part of his cunning plan.
He's not someone worth believing all the time.