ON ONE WALL of Stephen Bannon’s office in the West Wing of the White House is a large whiteboard with a list of promises the president made on the campaign trail. Most of them fit the nationalist, nativist, populist programme that Mr Bannon has done more than anyone apart from the president himself to shape, but perhaps not all: one commitment is to build a safe zone for Syrian refugees. The president’s chief strategist is a revolutionary in a Ferragamo tie, an alumnus of Georgetown, Harvard and Goldman Sachs who rails against the establishment. He talks about building an alliance of working people that will hold power for 50 years.

As a political strategist, Mr Bannon follows a template he perfected at Breitbart, the provocative website he used to run. The Breitbart strategy is to take an extreme position and hope that readers or voters will follow three-quarters of the way there. At Breitbart, for example, illegal migrants are not just people who broke immigration laws, but potential rapists and drug-dealers. Political scientists refer to the range of ideas the public might be willing to accept at any one time as the Overton window, after Joseph Overton, who codified the concept. Mr Bannon specialises in moving that window. Given that most voters do not follow politics closely, rarely switch parties and are often willing to align their preferences to those of the party or candidate they favour, Mr Bannon and the rest of the Trump White House have considerable freedom to place the window where it suits them.

The president’s approval ratings may gradually slip to the mid-30s, as happened to George W. Bush in his second term. Perhaps some of the Midwestern voters who backed Mr Trump in the hope that he would bring back manufacturing jobs will be disappointed. His opponents will be energised at future elections, and in a country where opinions are split roughly down the middle, these marginal voters assume great importance. But it remains unlikely that his supporters will desert Mr Trump en masse. Incumbent presidents tend to do well in elections when the economy is growing robustly. Those questioning whether Mr Trump will be forced from office should remember this.

The president’s admirers describe him as “situational”, by which they mean he has no ideology to speak of and judges each decision that comes before him in isolation. That explains, they say, how he can denounce President Obama for bombing Libya to prevent its government from killing its citizens, then launch a cruise-missile strike against the Syrian government to do the same thing. The president often seems to be pursuing the Breitbart strategy, only then to head in the opposite direction. On April 12th he cancelled a federal hiring freeze he had ordered in his first week in office; decided against labelling China as a currency manipulator; endorsed the Export-Import Bank, which provides finance to big companies like Boeing; and declared NATO relevant after all, breaking three campaign promises and abandoning one favourite theme in a single day. A little over a month later he changed direction again, declining to endorse explicitly NATO’s article 5, which says that an attack on one member is an attack on all, and pulling out of the Paris agreement on climate change. There is no consistent thread running through what he does; he can change his mind at any moment.

One of the president’s informal advisers says he cares more about getting something that looks like a win than about pursuing any particular policy. That would explain why he sometimes seems unaware of the details of policies he has advocated. When his administration on its 100th day in office got close to pulling out of NAFTA, it came as news to the president that some of his voters benefited from membership of the trade block.

A permanent fit of absent-mindedness

Much of the scandal that has roiled the Trump administration could be explained this way. The decision to hire Michael Flynn as national security adviser, which has been the cause of so many of the president’s troubles, was taken without seriously considering advice from the outgoing administration that picking someone for that role who was under federal investigation for working for other countries might be a bad idea. Likewise, the sacking of James Comey as head of the FBI, which some have seen as part of a well-thought-out plot, could equally suggest an absence of planning. The president may have been unaware that firing the FBI director after he declined to halt the investigation of Mr Flynn was an unusual move and would raise suspicions of a cover-up. This is no defence: the presidency is not a round of golf, where lousy players get a generous handicap to even things up. But Mr Trump probably does not realise that he is trampling on America’s political norms, changing the way the country is governed through profound absent-mindedness.

To his backers, the continuing involvement of his children in Trump companies, far from being evidence of corruption, is a reminder of all that he has sacrificed to be president. They see the travel ban the president tried to impose on visitors from six Muslim-majority countries, which is still stuck in the courts, not as an attempt to enact the Muslim ban that he had promised on the trail, but as a reasonable effort to reconcile America’s traditions of non-discrimination with the president’s responsibility to protect its citizens. The never-ending stories about Russia, which tend to be misunderstood as an accusation that Vladimir Putin decisively influenced the result of the presidential election, are dismissed as inventions by liberals to explain Hillary Clinton’s failure. Given how few Clinton voters the average Trump voter knows, that explanation can seem plausible to them.

How are voters likely to respond to this way of governing? Not by filtering out the noise from the latest outrage, then calmly taking each policy change and feeding it into a mental equation that recalibrates their level of approval for the president. Instead, to the extent that most people are thinking about politics at all, they are making judgments about whether the president is trying to do the right thing or is fundamentally malign. Such judgments are shaped by geography, education and skin colour, and are subject to groupthink: in mid-May 80% of Trump voters told YouGov that they see criticism of Mr Trump as an attack on “people like me”.

Those who watch or listen to the news have their view of the president’s good intentions confirmed when they find their place in their partisan trench reinforced by attacks on their opponents. Some of the most prominent conservative broadcasters—Rush Limbaugh on talk radio, Tucker Carlson on Fox News—do not support everything the president does so much as show allegiance to the tribe by denouncing those who denounce him. One of Mr Limbaugh’s favourite themes is the similarity between American liberalism and sharia law. Even for someone who is unsure which party is the more conservative, a choice between a perhaps flawed but well-meaning president on one side and fundamentalists on the other does not take much reflection.