As the US shutdown enters its fourth week, the president is starting to look for a way out

There is an inevitability about the deadlock in the United States responsible for the longest shutdown of (parts of) federal government. As we wrote when the shutdown, which is now in its 22nd day, had just started, “these things are resolved when the heat of public opinion becomes too great for one side to bear”.

Well, public opinion has not been going Donald Trump’s way. Since mid-December his approval rating has been shifting slightly but steadily against him. The all-important metric is who gets the blame for the impasse. More Americans blamed President Trump for the shutdown than blamed congressional Democrats from the start, but since Christmas the proportion blaming the president has risen from an average of 45 per cent to 49 per cent.

The other factor, which was emphasised when the US stock market dived over the holiday period, is the economy. As we report today, US markets are increasingly worried by the effect of the shutdown on the prospects for growth this year.

No wonder that, underneath the bluster, there are signs that the president is looking for a way out of the standoff. This week he managed to contradict himself within minutes on the question of whether or not he would declare a state of emergency, allowing him to pay for his wall on the Mexico border without congressional approval.

So far Nancy Pelosi, the leader of the Democrats in congress, has played a tough and careful game. She knows that the president has picked a fight with reality and that as long as the Democratic Party can stay out of the line of fire he can only lose. He refuses to accept that he ever claimed that Mexico would pay for the wall, and he plainly hoped that its value as a symbol of his determination to restrict immigration would be enough to sustain him in his clash with congress.

But the Democrats in congress have not given him the chance to paint them as soft on immigration, making the case that there are better uses for $5bn in paying for firm but compassionate immigration control. Again, they are on the right side of public opinion, which opposes the wall by about a 20-point margin.

So Mr Trump is in a tight spot. The wall is of huge symbolic importance to his enthusiastic supporters, but most American voters see it as a waste of money. He is running out of time to compromise with reality.