You can feel the excitement in Fox News’s reports that a DHS spokesman, backing the claims that Trump has now walked back, has confirmed that the migrant caravan that has just entered Mexico includes ‘gang members’ and people with ‘significant criminal histories’, as well as people from the Middle East. How hot and uncomfortable they must be, walking all that way in an explosive vest.

You can feel the disappointment in CNN’s report that by November 6, the migrant caravan ‘could still be somewhere in the middle of Mexico’, and well short of what CNN recommends as the ‘safest route’, to San Diego via Tijuana. How disobliging of the Hondurans to arrive too late to influence the midterms, and offer themselves up as cannon fodder in the Democratic attempt to retake that modern Alamo, the House of Representatives.

For professional reasons, the Democrats and their media supporters would prefer to schedule the migrant massacre for the first week of November. They want to use the migrant caravan as cannon fodder in their campaign against the president. Nothing would gratify them more than Donald Trump ordering more troops to the border, or complaining that the law forbids him from slaughtering brown people. NBC News tells us that the migrants call their road the Via Crucis Migrantes, the ‘Migrants Way of the Cross’. Only the Devil himself would use the Army against a cry for redemption.

Yet while the desperate of the global south march towards where The Wall is supposed to be, the Democrats are marching into an electoral wall, by identifying themselves with uncontrolled mass immigration. As Talleyrand said of the restored Bourbon monarchy, they have learnt nothing and forgotten nothing. The Democrats have forgotten nothing in their catalogue of vanities, and learnt nothing from their defeat in 2016. You don’t win votes by taking the same side on an issue as a group called Pueblo Sin Fronteras, who admit to having organised previous caravans, and to playing a supporting role in this one.

When they signal their virtue, the Democrats expose their distance from voters’ concerns about the economic, legal and cultural consequences of immigration. Of course, the Republicans are also doing little more than signaling their virtue by shouting about law and order, and sticking it to the Mexicans. But while the Democratic strategy is cynically foolish, the Republican strategy is cynically effective. The domestic politics of the migrant caravan may be a double act of inanity and cynicism, but the electorate will not applaud the actors equally. The Democrats are cueing up the Republicans’ electoral punch line.

‘Every time you see a Caravan, or people illegally coming, or attempting to come, into our Country illegally, think of and blame the Democrats for not giving us the votes to change our pathetic immigration laws,’ Donald Trump tweeted on Monday. ‘Remember the midterms!’

Trump has excelled himself this week on the migrant caravan. Which is to say, he has shamed his office, and dragged his party and the American people into the gutter, but firmed up his base and retained the spotlight. The migrants may have the Statue of Liberty in mind, but the real symbol of modern America should be a giant Twitter icon or a water cooler. Trump has changed the direction of the tweetstorm and the topic of the conversation, from Brett Kavanaugh to South of the Border.

NBC News files the caravan under ‘The Trump Effect’. Really, it’s the other way around. Trump is the effect — the effect of a long-running bipartisan failure of responsibility on major issues like economic policy, financial regulation and immigration. We could add to that the casual incompetence and greed with which the United States has conducted itself in Latin America — all of the advantages of empire, and none of the responsibilities.

Earlier this week, Barack Obama emitted a pitiable tweet, claiming responsibility for the high levels of economic growth over which Trump has presided. Obama is no more likely to claim responsibility for exacerbating the migrant crisis in Europe, by smashing up Libya without a plan and not stabilising Syria when he had the chance, than Trump is to claim responsibility for helping start a mass flight from Honduras by recognising the rigged electoral victory of Juan Orlando Hernandez.

In slow motion, and over several decades, the United States has walked into the dilemma described in Jean Raspail’s racist yet percipient novel The Camp of the Saints (1973). In Raspail’s story, which became a bestseller in 2011 when it emerged that it was Steve Bannon’s preferred reading for the bedtime of the West, France faces a flotilla of desperate migrants from India. Like CNN and Fox, the former editorialising with images of women and children, the latter with images of adult males, the French in Raspail’s novel respond with a mixture of irresponsible sentimentality and racially-charged belligerence. And divided they fall.

This is what you get when you place an entire continent within your sphere of interest for nearly two centuries, permit the impoverishment of most of its people under corrupt but friendly regimes, and then exploit the undocumented labour of those able to escape. You will get much more of this, too. The midterms will pass, but all those desperate people will still be on your doorstep. So long as that doesn’t change, this will not be the last Caravan of the Saints.

Dominic Green is Life & Arts Editor of Spectator USA.