Thus far, Trump’s stay at the top of the polls for the GOP nomination has defied political conventions and expectations. Mistakes and gaffes that would have doomed any other candidate on planet earth have instead bolstered Trump’s standing in the polls. Most traditional pundits have been at a loss to predict when or if Trump’s polling numbers might come back to Earth, because Trump’s support isn’t governed by the usual rules of politics.

However, the last week hasn’t been good for Trump – and not in the normal way that weeks “aren’t good” for Trump. It’s not that he made mistakes (he did) or made a clown out of himself (he did). These are not new features for the Trump campaign and the fact that they regularly occur is already baked in. It’s that the Trump phenomenon has, over the last week, started to seem… well, less fun.

Jay Cost had a piece earlier this week that was one of the most prescient analyses of the Trump phenomenon that I have seen. He hit on one of the main aspects of Trump’s appeal that I don’t think enough people were giving attention to:

So, why is this working? Perhaps the better question is: Why shouldn’t it be working? After all, Trump’s pitch has worked for him for decades. Plenty of people made a mint during the Reagan boom, but only Trump turned his wealth into a personal brand—and he could do it because he is a character. He somehow manages to be simultaneously a man of the people and larger than life. He’s funny, witty, and disarming. Best of all, he seems to be hosting a party to which everyone is invited.

I watched the first debate live at the RedState Gathering with a raucous crowd several hundred strong, many of whom had come to see Trump perform. I wasn’t able to really hear much of what was said, but what was clear is that everyone in the audience who had come to cheer on Trump was having a great time. They loved his boisterous personality, his personal attacks, his larger than life style.

Last Wednesday, though, Donald Trump lost something more than the substantive argument over policy that occurred in the debate. He lost the feeling of being the fun candidate on stage. He had to stand there and get publicly dressed down by Carly Fiorina over his remarks over his looks, and issue what was the closest thing he will ever give to a crow-eating apology. As the debate wore on, Trump’s energy visibly flagged and the conversation moved inexorably away from him. Trump was left trying to force awkward high fives from Ben Carson and Jeb Bush to make himself the center of attention again.

The impression of a man who has lost his party mojo was reinforced yesterday when Trump petulantly tweeted that he was henceforth going on a boycott of FoxNews, then spent the entirety of last night tweeting passively aggressively about the FoxNews programs he was clearly sitting at home watching. The final capper was when the formerly boisterous and un-PC Trump actually suggested that the FCC ought to fine Rich Lowry for saying “balls” on air. In the span of one week, Trump has gone from the guy who would say anything to entertain a crowd to the scolding church lady complaining about standards on television.

The thing about parties is that they end. At some point, everyone runs out of gas, and the few conscious people who are left standing look around and realize that the party has worn them out and it’s time to go home and get some rest. So they start corralling their drunken compadres and calling taxis or heading for subway or whatever their plan is for getting home and getting into bed so they can face reality the next day.

Trump is increasingly looking like the guy who refuses to accept that the party is winding down and staggers around and berating everyone in a drunken slur for being such wimps and squares. While the party is going full swing, he was the life of the party; but now that everyone is trying to collect their wits and deal with real life again, he’s kind of tiresome and annoying.

For now, Trump is mostly succeeding at keeping people at the party, but his tone has already taken on an uneasy hectoring tone as opposed to a raucuous, party-leading one. This, I think signals the beginning of the end for Trump’s wild ride. If I had to guess, Trump might hold on to his lead through the end of October, but if he still has it by Thanksgiving, I’ll be surprised. The force of his personality, though considerable, just can’t keep the party going that long.