The continuing partial shutdown of the federal government undermines one common criticism of President Donald Trump even as it confirms another.
The overstated criticism is that Trump has turned the Republican Party into a cult of personality. He could raise taxes or promote taxpayer-funded abortions, according to this theory, and his supporters would applaud his brilliance and far-sightedness.
It's true that some Trump supporters speak cultishly of him. It's true, as well, that many Republican voters have changed their views, and many Republican politicians have adjusted their rhetoric, to match the president's positions. But the fact that Trump failed to persuade Alabama Republicans to unite behind his preferred Senate candidate - twice - is one of many pieces of evidence that his sway has real limits.
In mid-December, the White House seemed prepared to go along with legislation to keep the government fully funded without getting money to build a wall on the U.S.-Mexico border. But this willingness received withering criticism from Ann Coulter and others - criticism amplified by Fox News.
That criticism appears to have succeeded in getting Trump to insist on getting money for the wall. Congressional Democrats are unwilling to give it to him. The resulting lack of agreement on a funding bill has resulted in a shutdown.
The president's critics often liken Fox to state-run media outlets in repressive regimes. In this case, however, the president followed Fox's lead rather than the reverse.
Trump is not acting as though he can take his supporters for granted. He is acting, instead, as though an important subset of his supporters will abandon him if he does not deliver something they want.
That political judgment may be right. The number of people who would turn on Trump over lack of progress on the wall - who would refuse to accept that he had tried but been defeated - may be small. But he leads a minority coalition that cannot afford to shrink even a little.
Another criticism of Trump is that he lacks some of the basic skills that enable successful presidents to achieve their aims: Setting priorities, thinking ahead, matching means to ends or preparing for contingencies. Instead he acts on his impulses. Sometimes these impulses are inspired, but often they are not, and they shift.
The shutdown has illustrated these deficiencies. Trump could have avoided it while also securing wall funding last year, when Senate Democrats offered it in return for codification of the legal status of illegal immigrants who came here as children. Instead he rejected it and held out for wildly ambitious goals, such as a reduction in legal immigration that split Republicans and that he had not even embraced during his presidential campaign.
Such a deal no longer appears to be on the table, since Democratic attitudes on the wall have hardened and Democratic strength in Washington has increased.
If budget brinkmanship were, or became, the only way to get financing for the wall, the administration could have prepared for it better. The White House could have put out word to congressional allies that it was going to take a stance that made a shutdown likely. It could have had a plan for implementing a shutdown instead of scrambling once it had already begun, as it is now doing.
Above all, Trump could have avoided promising in advance that he would to take responsibility for a shutdown when actually having one was inevitably going to mean that he was going to try to blame Democrats for it.
Any of these alternative courses would, however, have required a modicum of long-term planning that does not appear to come naturally to this president. We are now on a course that Trump took with no exit strategy other than hoping that Democratic or swing voters start to put pressure on Democratic politicians to give in to him - even though he already said, weeks ago, that he was the one responsible for the shutdown.
Trump stumbled into this situation because of a fear of losing supporters and an inability to devise a long-term strategy for placating them. Unfortunately for a lot of Americans, that same combination is going to make it hard for him to get out of the shutdown.