The moment the president declares a “national emergency” — a decision that is entirely within his discretion — he is able to set aside many of the legal limits on his authority. — DefenseOne.com 8 Dec. 2018
"You know, they have a word – it’s sort of became old-fashioned – it’s called a nationalist. And I say, really, we’re not supposed to use that word. You know what I am? I’m a nationalist, okay? I’m a nationalist. Nationalist. Nothing wrong. Use that word. Use that word." — Donald J. Trump, October 2018
Donald Trump should be taken literally and seriously, if for no other reasons than that key portions of his core supporters take him literally and seriously. So a wall at the US-Mexico border means a wall, and a national emergency means an emergency of the Nation.
This is important.
There is no "crisis of the Republic," except that posed by Mr. Trump and that hard core of authoritarian-populist followers. There is no emergency of the American State. There is, though, an emergency-level threat to the American Nation if, if only if, you see that Nation with its traditional modifiers: in fullest form, "White, Christian (i.e.,) Protestant, Anglo-Saxon Nation" — with recent wishy-washiness allowing in some conservative Catholics and even right-wing "White Jews" (yes, Virginia, that once was a fairly common term; check out Lenny Bruce).
The slow-motion threat to that Nation is in the demographic trend that will have White a US minority within a couple generations (2050 in one projection). The more immediate threats can be seen in the 2018/19 Frosh class in the US Congress and the religious composition of the US Supreme Court: until recently lacking a single real (Protestant) Christian, and now having one only ambiguously, depending on how "Papist" one sees a Catholic-raised Episcopalian like Justice Neil Gorsuch. Plus, of course, ethnicity of both the Supreme Court and that Congress, and, spectacularly, the color-coding — African-American — of the US Presidency 2008-16.
And we haven't even considered gender yet, with women on the Supreme Court and second in line of succession to the Presidency and, if she knows how to use the office, the second most powerful politician in the United States: the Speaker of the House, the Honorable Nancy Pelosi.
And what people see in the media. White "hegemony" is certainly gone, but more important — and this is a serious complaint — is the handling of religion. Outside of specials and The Religion Ghetto (and serious animation satire such as The Simpsons and South Park), religion and religious people are pretty much invisible. To recycle a formula of mine on TV characters, ordinarily, as far as we see, "They don't piss, and they don't pray."
Now there's really little President Trump can do about the larger, reality issues here. Dictator Trump, maybe. President Trump must deal with the edges of the issues and with symbols.
As symbols go, the Wall is great.
• A monument to Donald J. Trump, in its expense and uselessness all the more potent as an image of power (cf. pyramids).
• A symbol of American holiness as separation, preserving the purity of that American Nation from penetration by all the evils Trump can remember to name.
• A dike against inundation by the wog-gish flood, the horrifying Brownish Hordes, the embodiments of the forces of the post-Communist world that would, at least figuratively, "sap and impurify all of our precious bodily fluids".
And if Trump gets away with a National Emergency declaration over the Great Wall, there's a chance he'll keep pushing until he gets the powers to make real changes in the American State and remove the inconveniences of the Republic. There is justification (so to speak) in the arguments of authoritarian populism as a form of pure democracy, using the Leader-Principle to around convention, tradition, bureaucratic inertia, and institutional conservatism. And there are precedents; God knows, within living memory, there have been Nationalist precedents.
As Ursula K. Le Guin reminds us in The Dispossessed (1974), all walls are "ambiguous, two-faced"; and the Berlin Wall made the point very well that walls can keep in as well as keep out. If Donald Trump rides a continuing National Emergency from President of the United States to Leader of the American Nation, some of us citizens of the Republic, people in the United States but not of the Nation — some of us may find that Wall a barrier to escape from another round of ethnic cleansing, National purification.
If you're curious, my oath is to the Republic and the Constitution establishing it. If my courage holds, I'll defend both against all enemies, foreign, and domestic.