Executive “privilege” is risky because the president can’t actually make law. He can only direct traffic in such a way that it is still under a law that is already in place. As we have seen, presidential bobbing and weaving around congress sooner or later involves the federal district courts and the Supreme Court into making a decision as to the constitutionality of the use of presidential pens and phones. The only function of the executive branch is to enforce law, not make it. That is the job of congress no matter how much congress wishes to place their jobs on the shoulders of the executive and judicial branches. As far as the wall goes, congress has already approved the wall but will not approve the finances without quite a few strings attached. That is why the president is using other means of financial support to fund it.
We'll see what happens. The Dems in Congress didn't seem to care that many essential Federal employees were not being paid, yet had to work. Trump at least cancelled his vacation to be available for negotiations, while the opposition just took additional breaks.
I think it’s gutsy as heck......and smart. The president gets everyone paid including their back pay and then he vows to shut it down again if the Dems and a few Rhino’s do not come to the negotiating table. If the opposition to the wall do not come to terms then his warning comes to fruition and the opposition takes the hit in the voting booths at the next election.