President Donald Trump just gave a speech today on immigration policy, which was notable for its lack of actual details, while being heavy on rhetoric and fearmongering. That's about par for the course for Trump. But the most interesting thing Trump said was, in response to a shouted question, that he wouldn't actually be signing any executive orders until "sometime next week." Since next week is a rather momentous one on the political calendar, that leaves open the question of whether Trump will hold such a signing ceremony before or after (or even, conceivably, during) the midterm elections on Tuesday.

Why would Trump delay such a ceremony, if he truly is interested in rolling out a new policy? There doesn't seem to be any good answer to that question, really. Why didn't Trump end his speech today by sitting down and signing an executive order? Even just looking at it through a political lens, that would have made the most sense. Trump is quite obviously only really interested in the political benefits of a new immigration policy, which is why he's rolling it out now -- he thinks it'll be a great closing argument for the Republican Party's midterm campaign. So why wait on the actual policy?

There are three possible answers to that question. The first is one of pure logistics -- Trump had these brainstorms so recently that there simply hasn't been enough time for his aides to put together the actual language of such an executive order. This is exacerbated by the plain fact that what Trump would really like to do is completely unconstitutional or illegal. So his legal advisors have to take Trump's raw impulses and somehow come up with something that has even a shred of a chance of being upheld in court. That's tough to do, for obvious reasons, so it's perhaps understandable why they need a few more days to put something together for Trump to sign.

The second reason Trump might be waiting is to have an even bigger impact. He may be waiting until Monday to hold the signing ceremony, so it will be fresh on all the voters' minds the next day. This may be too cute by half, though, since many professional watchers of politics say that any new information or event needs at least two or three days to percolate, in order to change any voters' minds. Even the revelation of some deep and dark scandal doesn't move the needle at all when it happens too close to voting day. Trump may not know this, or may believe differently. We'll see what happens, next Monday.

But the third reason Trump may be hesitating now is the most likely one, really. Trump knows what he wants to achieve. The White House has even been foreshadowing it in the past few days. Trump wanted three things, we were told: (1) U.S. military patrolling the border, (2) an end to birthright citizenship, and (3) a total denial of all asylum claims for anyone arriving at the southern border. Thing is, though, none of these are legal and/or constitutional.

The United States military is completely barred from operating on domestic soil for law enforcement purposes. Period. It has been since the Posse Comitatus Act of 1878. That's a pretty solid precedent to try to ignore, in other words. Trump really wants soldiers patrolling the borders, and (as he flat-out admitted today) actively shooting at incoming immigrants. However, the law is clear: this is illegal. The military -- all 7,000 troops Trump either has down there or is now sending -- are completely restricted to support roles. They cannot actually patrol the border. They can beef up physical barriers (hundreds of miles of razor wire will reportedly be deployed), they can help out with things like drone surveillance, but they cannot detain or arrest any illegal entrants at all. If they stumble across such people, all they can do is to call up the Border Patrol agents who can make such arrests. Trump can talk tough about shooting rock-throwers all he wants, but that is in no way going to be the troops' primary mission. Far from it.

Trump claimed in an interview this week that he can end birthright citizenship with an executive order. He is wrong. This is part of the Constitution, ratified into being with the Fourteenth Amendment. As such, no president can change it by fiat. Even Congress can't do that, although plenty are now attempting to make the case that they can. To change it would really require another constitutional amendment, not merely Trump signing a piece of paper.

Trump's third priority is just as unrealistic as the other two. This was what was previewed by the White House before his speech -- that Trump was going to "shut down the border" to asylum claims. Only problem is, he can't actually do that. What most of the media fails to point out is that when the previous caravan got to the border earlier this year, almost all of the people in it legally presented themselves at border crossing stations and made their asylum claims. This was tough to do, since the border crossings only process a very limited number of such claims per day, which dragged the process out for many. But that's how most of them crossed -- because they know that this is the correct way to do it.

Trump initially wanted to just shut down all asylum claims from anyone crossing from Mexico. This isn't legally possible, he was told (obviously). So he decided the next-best thing would be to deny anyone crossing illegally from making an asylum claim. This is very probably also illegal. It will be up to the courts to decide, but physically being on American soil grants people certain constitutional rights they do not have elsewhere. But, again, this will be up to the courts to decide one way or another.

The fourth part of Trump's speech had not been explicitly previewed, but it's been in the works for a while, so it was no surprise to hear Trump say he's going to stop "catch and release" and instead just send people to "tent cities." This is a nice euphemism for refugee camps, it must be noted. Families and individuals will be housed in tents, on military bases or elsewhere.

Of course, if any of this actually gets implemented, the optics of it will be horrible. Say someone chucks a rock at a soldier, and the soldier shoots him. Think that video will go viral? How's that going to play in Peoria? It's one thing to watch video of, say, Israeli soldiers shooting Palestinian protesters at their border, but it's quite another to see a soldier wearing the uniform of the United States do the same thing. All it would take would be one such incident where someone catches the whole thing on video for it to become an explosive political issue.

Likewise those refugee camps. Videos of horrific suffering in refugee camps elsewhere in the world are one thing to watch on television news, but the same sorts of videos from Texas or Arizona are going to be quite different. Will the tent cities be surrounded by razor wire and fences? Will they be patrolled by soldiers? How is that particular imagery going to play, politically?

Which is why the most plausible explanation for Trump's delay in acting is that what he's going to sign next week (if, indeed, he actually signs anything at all) will fall far short of the promises he's blithely making to his base right now. He cannot order the military to actually patrol the border. He cannot overturn birthright citizenship with the stroke of his pen. He cannot simply refuse asylum to anyone crossing into the U.S. from Mexico. He can put up some tent cities and fill them with people, but even this will likely be immediately challenged in court. His legal team has doubtlessly explained all these realities to Trump, but Trump doesn't like this at all. So he's trying to have it both ways. He's vaguely promising grand sweeping changes, but he is actually pretty powerless to make any of these changes legally. So rather than signing something today -- which would give voters the time to figure out that Trump's action in no way matches his rhetorical promises -- Trump is going to sign something far less sweeping after the midterms are over, when it will no longer matter much what the voters think, one way or another.

Trump thinks going all-in on fearmongering will carry the day for him with the voters next Tuesday. He's not even pretending to be subtle about it, either. He's releasing last-minute ads that paint Democrats as being on the side of murderers. Republicans will save us all from the brown hordes, Trump promises. A vote for a Democrat is a vote to be murdered or raped in your own bed. As mentioned, none of this can be called even remotely subtle.

The question is whether it will work or not. And that's really up to all of us. Next Tuesday is going to chart the course of American politics for the next two years and beyond. We've seen the dark vision of the future from Trump -- refugee camps and live fire at the border. They're not using dog whistles anymore, they're using megaphones. The only way to shut them up is to hand them a shellacking at the polls. Anyone not currently in a coma needs to get out and vote next week, to be sure this happens. Because I for one don't like the vision of the future Trump unveiled today at all. And the only way to change it is to vote.

-- Chris Weigant

Follow Chris on Twitter: @ChrisWeigant