“We are entirely capable of bungling this opportunity to regain control of the House and Senate and the trust of the American people,” Harry Reid (Democrat, Nevada), the Senate minority leader, said to scattered applause. “It will take some doing, but we’re in this for the long and pointless haul.”

“We can lose this,” Reid added. “All it takes is a little lack of backbone.”

The Onion’s parodies of American politics are spot on. I’m still fond of such headlines as “Kerry makes whistlestop campaign tour from deck of yacht” and “Cloned Cheney lacks charm of original”. But this time they might just be off the mark. A gaping opportunity has opened up in America’s domestic debate; and whoever fills it stands to win big. Even the Democrats might just see it.

President Bush’s trump card since 9/11 has been national security. That much is a truism. But his real advantage has been the way he has framed national security. In his strongest moments he has welded Texan swagger to unilateralist clout. He has been able to satisfy the desire for revenge after the Al-Qaeda attacks and demonstrate that he is not some effete internationalist compromiser.

While Democrats have urged him to look to America’s alliances for help, Bush has scoffed. While Democrats have suggested that Iraq was a poor target for an anti-terror strategy Bush has relied on the popular notion that most Arab autocracies are not to be trusted and that Saddam was a particularly nasty tyrant, so what’s the big deal? He’s the national defender, the strong leader, the man who gets the big picture of what we’re up against.

But in the past few months the facts of international politics have forced Bush to take a subtler, more complicated tack. The low-level civil war in Iraq has taken its toll. The president’s patent lack of serious options against a potentially nuclear Iran has made him look adrift. But two issues have been deadly to his standing.

The first, oddly enough, has been his lame response to the Muslim cartoon riots. You would think this would be a no-brainer: a defence of free speech against Islamist bullies. But Bush was relatively quiet; and his State Department put out meek purrs of support for an isolated ally, Denmark. The man sounded like Bill Clinton.

The second has been Bush’s insistent refusal to acquiesce in the anti-immigrant fire stoked in the populist heartland for years. Nearly every day two of the country’s most popular television pundits, Fox’s Bill O’Reilly and CNN’s Lou Dobbs, inveigh against illegals pouring in over the Mexican border. They back vigilante groups to stop them; they want a wall; they want arrests and deportations; they cite the terror threat; and they are relentless in attacking Bush on the subject.

This populist xenophobia has its law-and-order right and union left variants. But Bush is unrepentant in his desire to find a way to help these immigrants live and work in America; and his business connections tell him the economy would hit a wall if immigration were halted. He also wants to woo increasingly important Latino votes to the Republican cause. And so this is a John Wayne moment he’d rather pass on.

The upshot is: he’s been looking a little wobbly to the gung-ho set. That’s when the Dubai ports deal hit. A rational look at the facts shows no real danger from a multinational company based in the United Arab Emirates taking ownership of six American ports. But the populists had their headline: “Bush to give ports to country tied to 9/11”. And nothing could deflate its rhetorical power.

Polls show overwhelming majorities of Americans oppose the ports deal. Almost half the country strongly opposes it. Suddenly Democrats pounced. “We have to have American companies running our own ports,” Senator Barbara Boxer harrumphed. Hillary Clinton wasn’t far behind. New York’s other Democratic senator, Chuck Schumer, has barely stopped hyperventilating since. As Rich Lowry of the National Review noted: “Republicans opposed to the deal have had to say, ‘We support free trade, but . . .’ Most Democrats don’t have to bother with the ‘but’.”

Meanwhile, competing immigration bills in Congress are dividing the Republicans right down the middle between their pro-business wing and their southwestern and heartland base. That base is already demoralised by continuing dislocation and disarray on the Gulf coast after Hurricane Katrina; and by fathomless spending in Congress.

The upshot? The president is stuck in Dubai-doo-doo and approval ratings in the upper thirties.

Could a Democrat outmanoeuvre Bush? Think of this as a possible campaign platform: get our troops out of Iraq and Arabs out of our ports. Stop the corporate power structure from depressing American wages and enforce real border control. Invest in energy independence and get the oil from Canada. Bring our boys home and keep our borders safe. Screw the Saudis and their best friends, the Bush family.

Think of it as a testosterone injection for the Democrats — an almost irresistible, if equally irresponsible, agenda to win back control of Congress in November.

Here’s my bet: if the Democrats don’t seize that platform, many Republicans will. And Bush will be powerless to stop them.

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