I'm sure there are many in Trump's hard core of supporters who will hold fast to their faith in the president and tell themselves that their beloved wall will get built eventually. This was the single most important promise Trump made, the one that distinguished him from his primary opponents, animated his supporters, drew out people who hadn't voted in years, and defined the kind of president he was supposed to be and the America he was supposed to create. And it's never going to happen. It is simply impossible to overstate the symbolic importance both the wall and the idea that Mexico would pay for it had in 2016. Everything about Trump was embodied within it: the xenophobia, the vision of a world of threats and danger, the belief that complex problems have easy solutions, and most of all, the desire to stand tall and humiliate others, which was so critical to voters who felt beaten down and humiliated themselves. That's why the preposterous notion that Mexico would pay for the wall was so critical: not because we need Mexico's money, but because forcing them to pay would be an act of dominance, making them kneel before us, open up their wallets, and pay us for their own abasement. Whenever a Mexican official would say that of course they weren't going to pay for a wall, Trump would tell his crowds, "The wall just got ten feet higher!" And oh, would they cheer, thrilled beyond measure at the idea of punishing Mexico for its insolence and showing them who the boss is. Yes, the wall was about fear and hatred of immigrants, but more than anything it was a vision of empowerment. But just look what Trump has been reduced to now:

Those are the words of a man who knows that he can't keep his promise. What accounts for Trump's apparent willingness to put off construction of the wall? There's the immediate need to keep the government open, and he may have realised that Democrats will not budge on this issue. He may also have realised that the wall is extremely unpopular, with polls consistently showing around 60 per cent of Americans opposed to it, even if it remains popular with Trump's base. Interestingly enough, the wall is more popular the farther you get from the border itself, which suggests that the people most unsettled by immigration aren't those whose communities have the most immigrants, but those whose communities are incorporating significant numbers of immigrants for the first time. And not a single member of the House or Senate who actually represents a border district or state - a group that includes both Democrats and Republicans - supports building a wall. Let's assume for the moment that this budget impasse is going to end without border wall funding. What happens then? Every time they revisit the issue, the administration and Congress are going to confront the reality that a wall along the entire 3200 kilometres of the border is utterly impractical, even if we were willing to pony up the money it would cost (estimates range as high as $US40 billion ($53 billion)). Since much of the border lies on private lands, a wall would require the use of eminent domain - which Republicans say they despise. Just imagine the news stories as the government seizes land belonging to farmers and ranchers so it can construct Trump's vanity project. That's not to mention the fact that in many sections the border lies in remote areas, meaning we'd have to spend billions to construct roads in order to get construction equipment to the right places. And keep in mind that we already have fencing along over 1046 kilometres of the border, including many of the most high-traffic areas. Donald Trump's latest tweets are the words of a man who knows he can't keep his promise. Credit:AP

Where does that leave the wall? The most likely outcome over the long term is that Congress will appropriate some money for new construction, though not nearly the amount a 3200-kilometres border would cost. The Department of Homeland Security already has a plan to build 160 kilometres worth of walls in some critical areas. That may well happen, along with other beefed-up border security efforts. Taken together they'll make crossing into the US more difficult - but they won't be anything like the formidable wall Trump promised. But Trump may still try to declare that he built a "wall," even if many people laugh at him for saying it. After all, it was all just marketing from the beginning. Compare it to the extra fictional floors in Trump's buildings: In order to make them seem bigger, Trump would regularly decree that the lobby of a building constituted floors 1-9 or 1-14, so he could claim that the building had more stories than it actually did. It didn't fool anyone, but he kept doing it all the same. Loading As the months and years pass, Trump's voters may realise that they got sold a myth, and he was never going to deliver. Or maybe not - for them, the story may have been so compelling that it doesn't matter whether it came true. But in the real world, there won't be a wall spanning the border, and Mexico sure as hell won't pay for it. No matter what the president tries to claim. Washington Post