When teaching an introductory American Government course to freshmen who enter college with a wide range of skills and prior courses in the subject I have found it safest to start things with the basics. Real basic. We spend a week at the beginning covering "What is government and why does it exist" stuff before we even begin the Constitution and specifics.
One of the first tasks is to explain conceptually (again, without specifics) what government does. Almost any example you can conjure up fits into one of a small number of boxes: maintaining order, providing a forum for decision-making, providing public goods, organizing for collective defense, and so on. One of the most underappreciated of these basic tasks is enforcing predictability. No economic transactions, for example, are possible without predictability – X and Y must know that if they make a contract, either party violating the agreement can be taken to a court that will enforce it. Society functions very poorly without this; if you can't plan for the future in some very basic ways and rely on a few unexceptional assumptions (i.e., you don't need to spend 24 hours per day defending your home. You can leave it and feel reasonably confident that no one will break into it because they know the likely consequences) then your society breaks down. Government, then, is a bit like the weather forecast – it's more useful when telling you about the future than the present.
Trump supporters cite the president's rashness, lack of forethought, and unpredictability as an asset; he will "shake things up" or whatever. Who knows what he'll do from minute to minute. Wild card!
In reality, we will be lucky if that approach doesn't get us all killed. International actors are wringing their hands with the sudden inability to rely upon American intentions as a known quantity. The domestic policy process has ground to a halt in a way I never thought possible with the House, Senate, and Executive branch unified under one party. And increasingly citizens don't know if they can trust interacting with their own government. We have a reasonable idea of what the law is now, but what presidential mood swing will reshape it in six months?
Three recent examples stick out. First, he threw transgendered people under the bus after making explicit promises during the campaign to be "hands off" on those issues. Second, he told Congressional Republican leaders that he would make a deal with them on the debt ceiling and then, unprompted, cut a different deal four hours later without telling them. Never mind that legislating and inter-branch relationships depend almost entirely on trust, norms, and informal institutions. Third, he retroactively turned DACA into a trap to lure immigrants to their own deportation.
The DACA example is particularly insane. Think about what just happened. The federal government told people "Look, it's better to know that you're here than to have you here lurking around in the shadows. And it's not your fault mom and dad brought you here when you were four. So, come forward and we'll suspend deportation." Something like 800,000 people, with every intention of doing the Right Thing and following the rules, took advantage of it. Now, a few years later the same federal government (albeit under different leadership) says "lol jk, we're going to use the information you gave us to find and deport you."
This incentivizes the worst possible behavior, of course. It encourages immigrants to live in hiding and to go to extremes to avoid interactions with the state. Because in all honesty, those people have zero reason to trust the government at this point. None. Frankly, immigrants and transgendered soldiers aren't the only people with cause for skepticism. We all do. With no meaningful sense whatsoever of what is constitutional or legal, who the hell knows what this guy is going to change next? Hell, they're already talking about taxing 401(k) type contributions retroactively. Hey remember that money we said for 30 years that you could put away tax free? Ha ha jk give us a third of it! That'll really encourage people to save and plan for the financial future, right?
There's no value in going slippery slope here and pointing out what it looks like when this thinking is taken to its conclusion. Suffice it to say that "unpredictable" is just about the last adjective we want to be using in reference to the government and the law. No matter how much mouthbreathers with no understanding of – well, anything really – think it will be So Awesome to shake things up and show them politicians what's what, predictability is actually one of the fundamental objectives of any government. Without it life won't necessarily revert to nasty, brutish, and short but it will be a lot less pleasant than it needs to be.