They take our jobs

Opposition to Mr Bush's trade policies comes mostly from the Democrats. The Central American Free Trade Agreement (CAFTA) squeaked through the House last year by 217 votes to 215. Only 15 Democrats backed it—and unions promptly vowed to punish the “CAFTA 15”.

Democratic presidents are usually more supportive of free trade than their party, perhaps because a president represents the whole nation, not just a district with a steel mill that might close because of imports. Hillary Clinton, the Democratic frontrunner for 2008, is a free trader. But it is not impossible that the party's increasingly angry base could nominate a protectionist in 2008. The party's vice-presidential candidate in 2004, Senator John Edwards, voted against cheap textile imports and then made stump speeches about a 10-year-old American girl who, he said, couldn't afford a winter coat. According to Gallup, the proportion of Americans who see foreign trade more as an opportunity for growth than as a threat to the domestic economy fell from 56% in 2000 to 45% last year.

While many Democrats want to curb the inflow of foreign goods, many Republicans want to curb that of foreigners. Mr Bush says the American economy “could not function without” immigrants. Tom Tancredo, a Republican congressman from Colorado, disagrees. He argues that the costs of immigration outweigh the benefits: immigrants' children must be schooled at taxpayers' expense, and their willingness to work for a pittance drags down the wages of unskilled Americans.

He thinks that America's borders could be secured “relatively easily” and at “minimal cost” by building hundreds of miles of fences and deploying troops to patrol them (which would be good training, he says), and by punishing firms that employ illegals. He thinks the House would back 50-60% of his agenda—a tough anti-immigration bill passed late last year and is now in the Senate—and he hopes to make immigration an issue in the November mid-term elections.

It will be. Many non-Hispanic Americans see illegal immigration as not merely an economic threat, but also a cultural one. In a recent poll, only 8% of respondents thought the problem “not very serious”, while 63% thought it “very” or “extremely” serious. The final “isolationist” issue, foreign aid, is not yet electorally significant, though polls show Americans tend to think their country is too generous.

One reason to ignore the growth in isolationism in the short term is Mr Bush. He has made it clear he has no plans to change course. Iraq will be his legacy, so he has to see it through as best he can. He has compromised on free trade before, and may do so again, but few doubt where his preferences lie. On immigration, he seems sincerely liberal and convinced that Republicans can woo the swelling Hispanic vote. And on foreign aid, who'll notice a few odd billions in a budget of $2.77 trillion?

Optimists point out that America has always had a vocal isolationist minority. And surely globalization—more travel, ever deeper economic integration, common threats (such as global warming and terrorism)—mean that America cannot do it alone. Francis Fukuyama, a famously optimistic professor at Johns Hopkins University, even thinks the Muhammad cartoon row could pull America and Europe closer together, as Europeans realise they have more in common even with Texans than with Islamists.

So the most likely outcome is surely that the current isolationist surge will fade away. But consider two things. First, greater integration and the war on terror have hardly brought the two sides of the Atlantic together. Meanwhile, despite his proud words in the state of the union, isolationism, broadly defined, has already tempered Mr Bush's policy. The public's exhaustion with Iraq makes it harder for the president to tackle Iran. He will also have to retreat on immigration if he is going to get something through.

A lot depends on leadership. For the moment none of the leading candidates for the presidency in 2008 is an isolationist and the favourite in some polls, John McCain, is even more of an interventionist than Mr Bush. But with so many voters angry about the mad world beyond their borders, America might yet end up with both a more protectionist Congress and a president who is more reluctant to throw America's weight around.

Comprehension