Gratitude is due Andrew Sullivan for calling Donald Trump what he is in New York Magazine.

Con men usually know that a con has a life span, and not a long one. At some point, it will collapse because it is, in fact, bullshit. By then, the best con men have made the sale — think of “Trump University” — and moved on. They also know that keeping the suckers sealed off from other sources of contrary information is essential until the deal is done. You have to maintain a fiction relentlessly, dismiss or delegitimize external information that might get your marks to think differently, and constantly make the sale. You have to humor and flatter and bullshit all the time, until you’ve sealed the deal.

And Trump is really, really good at this. In fact, it’s his chief skill, along with his instinct for the easy mark and another human being’s vulnerable spot. It has worked many times before. It’s at the root of his entire shady business career. His problem now, however, is that this is the biggest of all cons, if you’re playing at a presidential level, and is also the longest. It has to be sustainable for at least four years. And that’s an extremely long time to keep it alive.

This is why, it seems to me, Trump tweets so often and so aggressively. It’s his chief mechanism for keeping his dupes under his spell, for sustaining the narrative of the con while reality tugs at it. He’s making the sale every news cycle of every day because the alternative is the whole thing crashing to the ground. It’s also why he keeps holding rallies. You need that kind of mass crowd hysteria to sustain a con — “America Is Great Again!” — that might otherwise be fraying at the edges. It’s why he lambastes the media. Their role in undercutting the con — in presenting the arguments against it, in raising suspicions about the con man himself — is deeply destabilizing to the project. And it’s why he has to lie, and lie with greater and greater intensity and frequency.

And sure enough, the rate of Trump’s lies is accelerating, as the con ages. All six of the last six weeks rank in the top ten most dishonest of his presidency, as the indefatigable Daniel Dale has noted. Last Tuesday, Trump actually made the subtext text, in a speech to a Veterans of Foreign Wars national convention: “Just remember, what you are seeing and what you are reading is not what’s happening … Just stick with us, don’t believe the crap you see from these people, the fake news.” Some have analogized this to Orwell’s vision of totalitarianism. But it is not as sophisticated as that. It’s just a con man getting a little rattled, as his trade war is beginning to wreak havoc in the Midwest.

When you have brazenly declared that such wars are easy to win, and agriculture in the heartland is nonetheless reeling, and manufacturing is increasingly jittery about the cost of imported steel, what else are you going to do? Well, you can bribe the farmers with some $12 billion. Or ask companies and their workers to be patient. But some in the middle of the country will still start doubting — and his polling in three Midwest swing states that gave him the presidency is now slipping. He’s at 36 percent approval in Wisconsin and Michigan in the latest NBC poll, and 38 percent in Minnesota. That VFW appeal — and his visit to Illinois and Dubuque, Iowa, yesterday — is a sign, it seems to me, of a little desperation.

Desperate is insisting that what is clearly the word would — from the tape and the tone and the sentence structure of his Helsinki press conference — is actually the word wouldn’t. Desperate is responding to the Carter Page FISA documents by insisting that they say the opposite of what they actually say. Desperate is insisting that when the president said no directly to a reporter asking whether he believed that the Russians were still meddling in American democracy, he was actually not answering the question, even as he was looking at the journalist when he said it.

Desperate is banning a CNN reporter from a press conference because she had previously asked difficult reality-based questions about Michael Cohen — and then quibbling over the term ban. Desperate is a sudden Obama-like truce with the E.U. on trade. Desperate is the attempt by some House Republicans to impeach Rod Rosenstein, a move that has not even been cheered by the far-right media, and that is swiftly deflating. Desperate is doubling down on the “witch-hunt hoax,” while the chief money guy for the Trump Organization, Allen Weisselberg, gets a subpoena, and Michael Cohen’s lawyer says of his client, who knows far too much, “He has hit the reset button; he’s made a turn — to be on his own, speaking the truth.” More desperate still is Rudy Giuliani saying of Michael Cohen last night, after Cohen told CNN that Trump did indeed know in advance of the meeting in Trump Tower with an agent of the Russian government: “He’s been lying all week; he’s been lying for years.”

No, this is not an unraveling. But the con is definitely fraying badly. And it is not going to get easier to keep patching it up as time goes steadily by.