Everyone knows how useful a dead cat can be, right? The Australian political strategist - and Tory campaign chief - Lynton Crosby is credited with coming up with the dead cat ploy. It has the great virtue of being as simple as it is colourful. When, Crosby says, you are in a hole or faced with the tricky task of diverting attention away from some unwanted piece of news you should throw a dead cat onto the table. Hey presto! No-one is talking about the bad news; everyone is talking about the dead cat on the table.
Donald Trump deployed the dead cat tactic yesterday. His proclamation - to call it a mere announcement fails to do it justice - that President Trump would ban muslims from entering the United States (with, it should be noted, a generous exception for muslims serving in the US military) is the biggest, deadest, feline anyone has seen in months. If it weren't so stinking you could almost admire the man's audacity.
But Trump needed to do something to distract attention away from the fact his campaign is in trouble. Granted it is the kind of trouble to which many of his opponents can only aspire but everything is relative and, like any balloon, Trump's balloon cannot survive a puncture.
A new poll in Iowa revealed that Trump is losing ground to the almost-equally-improbable Ted Cruz. Before Trump deployed his dead moggy that would have been the story of the day. But Trump, a narcissist even by the standards of the people who seek the American presidency, could not put up with that. Hence the dead cat.
We have been waiting for months, it is true, for Trump to fall and there have been moments when even those of us sure that his campaign will crash eventually have had to cause to wonder if, just perhaps, the madness afflicting the American conservative movement will this time prove ineradicable. I mean, it can't go on like this, can it? But what if it does?
Sometimes astonishing things do happen. Six months ago I could not conceive circumstances in which Jeremy Corbyn could become leader of the Labour party. In a world in which that is possible who is to say Candidate Trump is any more implausible?
Except he is and remains so. Perhaps it is a failure of my imagination, but I still cannot believe that Trump will actually do very well once the actual voting begins in February. A lot can - and most likely, will - change in the next six weeks.
The problem with Trump is that he is a loser. (Well, that's not the only problem with him but it's still a large and important problem.) Nothing he can do or say can change that. He cannot possibly win a general election and, eventually, GOP primary voters will appreciate that handing him the nomination hands the White House to Hillary Clinton.
Perhaps this time it will be different. Perhaps this time the fever will not abate. But six weeks is a long time in the primary season. Trump may yet do well in Iowa. Other cranks - Pat Robertson, Rick Santorum - have done so in the past. But he cannot win. Not in the longer-term. And that means he's not likely to prevail in the short-term either.
In any case, how does Trump top this? What fresh spectacular can he pull-off? Anything after this is going to seem small beer and feebly unimaginative. And since outrage is Trump's currency is follows that his campaign is soon liable to be subject to the laws of diminishing returns. He's heading for a crash.
Because that joke's not funny any more. The fact that plenty of Americans are mad as hell and plenty of these citizens are happy to flirt with the idea of President Trump does not mean they intend to consummate the relationship. We have been down this path before, albeit rarely quite as colourfully or grotesquely.
True, Trump's ascendancy is only the first of the GOP's problems. Once the party has rejected Trump it must find a way of rejecting Ted Cruz too. The Texas Senator - a status that, I'm afraid, shames that great state - is arguably more dangerous than Trump since he contains a superficial gloss of plausibility.
Still, the point remains: Trump is in trouble. It remains interesting and significant that his puffed-up campaign has survived so long intact - and in the longer-term that is nothing but bad news for the GOP - but it is heading for collapse. When that happens, I still predict that collapse will be swift and total.
Hence the dead cat. But the problem with the dead cat strategy is that it offers only momentary relief. It doesn't answer the problems that necessitated its deployment in the first place. And Trump doesn't answer those problems because he cannot answer them.