Of that listing I would say only Sec Mattis and CoS Kelley would have the understanding of the deep danger we are in and would actually try to represent the ideals of the Constitution. A close second is Sec Nielsen. I think she understands the gravity of the situation (even if Sen Graham doesn't) and may possibly conspire with Mattis and Kelley to consider 25.
AG Sessions, even though, attacked daily would never be disloyal regardless of the mental state of Mr Trump.
VP Pence sold his soul for the agenda above all else, so why would he care? I think Sec Pompeo falls into this category.
The rest are Trump tools and would never consider being disloyal.
I think one can see the underlying motif here. Fealty to Mr Trump or to uphold the Constitution and its ideals.
I argued long ago 25 would not be viable. I have long argued impeachment won't work. The only option left is to vote him out. Sen Graham thinks he will win 2020. I think we have a lot of delusional folks running government. The sad fact is, unless the Democrats can find a persuasive message, there is a real possibility Mr Trump would win 2020.
