FOR many Americans, it's a mad, mad, mad, mad world out there, and getting worse. During the Salman Rushdie affair 17 years ago, angry Muslims were content merely to call for the death of the allegedly blasphemous author and his publishers. This week, they were calling for the death not only of some allegedly blasphemous cartoonists but also their compatriots. And people from neighbouring countries. And Jews. And, inevitably, Americans.

What's the point, some Americans grumble, of engaging with such people? We gave the Iraqis freedom, runs the argument, and they repaid us with roadside bombs. Palestinians got the vote and used it to elect terrorists. And dealing with the rest of the world is scarcely more rewarding: old Europe sneers at us, the Chinese steal our jobs and Mexicans are quietly re-conquering the south-western United States. Wouldn't it be simpler to build a fence around our vast, rich, sane nation and let the rest of the world go hang?

It is a sign of the appeal of such sentiments that George Bush devoted much of his state-of-the-union speech to them.

“The road of isolationism and protectionism may seem broad and inviting—yet it ends in danger and decline...America rejects the false comfort of isolationism...Isolationism would not only tie our hands in fighting enemies, it would keep us from helping our friends in desperate need...American leaders—from Roosevelt to Truman to Kennedy to Reagan—rejected isolation and retreat, because they knew that America is always more secure when freedom is on the march.”

Mr Bush oversimplified, using one word—isolationist—for several disparate opponents. But he is right to worry. Partly in reaction to the president's hyperactive foreign entanglements, various forms of isolationist sentiment are indeed on the rise. A Pew poll in October found 42% of Americans agreeing that the United States “should mind its own business internationally and let other countries get along the best they can on their own.” That figure had jumped by 12 points in three years to its highest level since the mid-1970s (after the humiliation of Vietnam).

Although Mr Bush was hardly fair when he described all advocates of a less muscular foreign policy as “isolationist”, he has correctly identified one of the strongest currents against which he must swim. Many Americans wish to disengage from the world in one or more of four ways: by fighting fewer wars, by trading less freely, by allowing fewer foreigners into their country or by giving less foreign aid.

The purest isolationists, ironically, are to be found in the president's own party. Since Mr Bush came to office promising a “humble” foreign policy, they feel betrayed that he has practised the opposite. “Why would a president use his state of the union to lash out at a school of foreign policy thought that has had zero influence in his administration?” fumes Pat Buchanan, a former presidential aspirant and voice of the GOP's nativist wing. The answer: “His foreign policy is visibly failing, and his critics have been proven right.”

Iraq never attacked America, argues Mr Buchanan, so America did not have to attack it. As for the idea that America's security depends on ending foreign tyranny, that is “noble-sounding nonsense”, writes Mr Buchanan. “Our security rests on US power and will, and not on whether Zimbabwe, Sudan, Syria, Cuba or even China is ruled by tyrants. Our forefathers lived secure in a world of tyrannies by staying out of wars that were none of America's business.” Mr Buchanan thinks foreign aid is “the looting of America for the construction of the New World Order”. He is proudly protectionist and he fears that Hispanic immigration threatens not only America's survival as one nation but also Republican dominance of American politics, since Latinos usually vote Democrat.

Mr Buchanan has been singing this song for some time: it was part of his pitchfork rebellion against Mr Bush's father in the Republican primaries in 1992. But in damning the Iraq war and the use of force to spread democracy, Mr Buchanan is part of a much broader (and potentially more potent) movement.

On the right, there are two main groups: small-government conservatives and foreign-policy realists. The former point to the huge cost to the taxpayer of the Iraq war and the Pentagon (see article). The latter, typified by Brent Scowcroft, the first President Bush's national-security adviser, think that the old policy of propping up Arab strongmen brought “50 years of peace” to the Middle East.

For different reasons, almost everyone on the left opposes the war. The people who have enough spare time to go on marches and listen to Cindy Sheehan tend to think “BusHitler” invaded Iraq to enrich Halliburton. A larger, quieter group thinks the administration launched an avoidable war and botched it. Overall, the proportion of Americans who think the Iraq war worth fighting has fallen from 70% in April 2003 to about 45% now.

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 globalisation—more travel, ever deeper economic integration, common threats (such as global warming and terrorism)—mean that America cannot go 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.