For months, critics of the president have been told that they should take Trump’s words seriously, but not literally.

On Wednesday night federal district judge Derrick K Watson refused to take the bait. He insisted that Trump’s words on “banning Muslims” should be taken seriously and literally.

Trump's devastating new travel ban is built on a harmful myth | David Miliband Read more

Judge Watson made headlines when he granted a temporary restraining order halting Trump’s latest effort to ban entry of people from six predominantly Muslim nations into the United States.

The judge found that the executive order violates the constitution’s establishment clause and discriminates against a religious group.

His decision galvanized attention because it set up a new clash between Trump and the judiciary, a clash that the president eagerly took up when he told a large and supportive audience in Nashville, Tennessee, that the judge’s order striking down what he called a “watered down version of the first order” was “an unprecedented judicial overreach”.

Yet as important as substance of the judge’s decision, and the clash that it foretells, is, what may be even more important is the lesson that it offers about the enduring power of language.

The judge set out to determine if the revised executive order, which now makes no reference to religion, was simply a pretext for an unconstitutional act of religious discrimination. To do so he recalled the many things that the president said about the purpose of the executive order he issued, both before and after he took office.

Watson insisted on taking literally Trump’s electioneering statement: “Donald J Trump is calling for a total and complete shutdown of Muslims entering the United States.” In addition, he offered a long list of statements to that same effect made by Trump and his spokespeople.

He called particular attention to the statement of Rudy Giuliani when he went on television to explain how the initial executive order came to be. The judge reminded the readers of his opinion of what Giuliani said: “When [Trump] first announced it, he said, ‘Muslim ban’. He called me up. He said, ‘Put a commission together. Show me the right way to do it legally.’”

The judge tellingly referred to what he called the “plainly-worded statements made in the months leading up to and contemporaneous with the signing of the executive order, and, in many cases, made by the executive himself” that, Watson insisted, “betray the executive order’s stated secular purpose”.

The distinguished law professor Alan Dershowitz was quick to take to the airwaves to analyze Watson’s decision and to venture predictions about its ultimate fate. Just as he had done in February, when he discussed the judicial order about the president’s first travel ban, Dershowitz pointed to the president’s broad powers in the area of immigration and confidently predicted that Judge Watson’s decision would be overturned on appeal, if not by the ninth circuit court of appeals, then by the supreme court.

Dershowitz may be right about the ultimate fate of the latest judicial imposition of restraint. But, I think he misses a far more important and lasting legacy of this judge’s decision, namely its insistence on listening closely to what is said and holding on to the belief that words do have “plain” meanings, meanings which no person, no matter how powerful, can wish away.

In so doing he won a small battle in the struggle to keep democracy and the rule of law alive.

What Judge Watson wants us to understand, whether we favor or oppose the travel ban, is that when words lose their meaning and their capacity to bind those who use them, neither democracy nor the rule of law can long survive.

In contrast, when citizens and officials insist on the integrity of language they nourish the hope that both will outlive current assaults on them.