A waiver probably wouldn’t pass..but this at least sends a signal within the military..which is a good thing.
I would not be too sure about that. I heard Mattis was up for this back in May. He was/is Joe Dunford’s mentor.
My guess is that a waiver would pass. In the first place, there's precedent for a waiver, so opponents would have to argue that in this particular case it shouldn't be granted. Republicans will have majorities in both houses, so the only way to block the waiver would be a filibuster in the Senate. Are Democrats really going to go to the mats with a filibuster over this minor issue, when there are so many other things they need to worry about? If they do, they risk Republicans using it as an excuse to invoke the "nuclear option" and abolish filibusters completely. Also, they have a ton of Senators from red states who will be up for re-election in 2018. Are those Senators going to oppose an extremely popular general (especially with the military) and thereby hand their Republican opponents an issue to bash them with? I doubt it.