Will Trump make The Wall a national emergency?

Will Donald Trump leap to his last resort and declare a national emergency to build his wall? I think he is sorely tempted if only to set down his marker with Nancy Pelosi. Whether he has proper legal and constitutional grounds for doing so remains a point of debate. But as the president and commander-in-chief he could argue that it is his firm belief that national security is at risk and therefore a wall is the only way of protecting the country from foreign marauders! It would be a tricky one for the high court or the appeal court or Supreme Court to argue against unless those opposed to it could prove that there is no such risk and that the president is making it all up for political reasons. But under the US constitution, the status of the president has some weight to it. He has executive rights. So if he goes down this route he might well succeed. But then he has to find the money from somewhere which doesn't require Congressional approval. The Pentagon is the obvious choice because it could be argued that if the Mexico border without a new wall is posing a threat to the security of the United States, then payment for and construction of a barrier/wall should be carried out by the military. This bit of the argument is probably more difficult to justify than having Trump override Congress by declaring a national emergency. But fortunately for the president, he now has an acting defence secretary who I guess is desperately keen to be nominated as the permanent Pentagon chief, in which case Patrick Shanahan will be more than amenable to providing funds for the construction of the wall from the defence budget. The service chiefs will NOT be happy, but as he is their boss, they will have to do whatever he says. Trump must be pretty pleased Jim Mattis stepped down when he did, because he, I think, would have kicked up a fuss. So, Nancy Pelosi, unless you can start thinking of a possible compromise solution that will keep Trump happy, a national emergency may be on the cards quite soon. I think it's going to happen!