Deflating as it is, the likely Donald Trump scenario is this: He burns hot for a little while longer; he says something really out there in the first debate that roils up the base but makes Reince Priebus and Karl Rove break out in canker sores; but by the time of the baseball playoffs maybe, his act gets old, and somebody else becomes the Herman Cain of October. Then, next year, the primaries will start, and he’ll have to get votes. He’s not going to be all that competitive in Iowa, so it’s New Hampshire where he’ll need to deliver something. And if he doesn’t, he’ll just go away.

That’s the pattern anyway. I seem to recall that at this point in 2011, Michele Bachmann had a pretty good head of steam going. So maybe we shouldn’t get too overheated about him.

But Trump is different from Bachmann, and even from fellow entrepreneur Cain, in one major respect: He doesn’t give a crap about the Republican Party. He cares about Trump. And don’t forget he has the power singlehandedly to make Hillary Clinton president. He knows it, and you better believe Priebus knows it, and it is this fact that establishes a power dynamic between Trump and the GOP in which Trump totally has the upper hand and can make mischief in the party for months.

How does he have the power to elect Clinton all by himself? By running as an independent. Two factors usually prevent candidates who lose nominations from running as independents. One, they lack the enormous amount of money needed to pursue that path (pay the lawyers to get them on 50 state ballots, etc.). Two, they have a sense of proportion and decency, and they figure that if primary voters rejected them, it’s time to go home.

Well, Trump has the dough and lacks the decency. In an interview this week with Byron York, he left the door open a crack to such a candidacy. And that would be all it would take. Given his fame and name recognition, he’d likely hit the polling threshold needed to qualify for the fall debates. And with that kind of exposure, he’d do well—enough. All he needs to get is 5 percent of the vote in Florida, Ohio, Virginia, and Colorado, and the Republican, whoever it is, is sizzled. Another electoral landslide.

The question is, would he? And the answer is, who knows? To York, he expressed awareness of the obvious drawbacks, pointing to the spoiler role he says Ross Perot played in 1992: “I think every single vote that went to Ross Perot came from [George H.W.] Bush…Virtually every one of his 19 percentage points came from the Republicans. If Ross Perot didn’t run, you have never heard of Bill Clinton.” He is—shocker—wrong about this, but what matters for present purposes is that he believes it, so maybe that means he wouldn’t follow through.

But he is an unpredictable fellow. Suppose Priebus and the GOP piss him off in some way, and he thinks the hell with these losers. Suppose he decides—and don’t doubt the importance of this—that an independent run would be good for the Trump brand in the long run. And suppose he doesn’t actually mind so much the idea of Hillary Clinton being president. We already know he retains a soft spot for old Bill. And he donated to Hillary Clinton’s senatorial campaign.

All that’s speculative. But even in the here and now this dynamic has consequences. It means the GOP can’t afford to offend Trump. This is why Priebus’s spokesman characterized the chairman’s Wednesday evening phone chat with Trump as “very respectful.”

And it’s why the other candidates’ criticisms of him have been a little, ah, restrained. Politicians aren’t always real smart about any number of things, but one thing in my experience that they almost always have a very keen sense of is risk. Members of Congress, for example, generally know exactly what percentage of their electorate they’re going to sacrifice by casting X vote. Jeb Bush’s Trump criticisms are muted because he has a lot to lose by offending Trump and his supporters. Chris Christie, who’s little more than an asterisk in the polls, has less to lose, so he’s willing to be a bit more blunt. Same goes for Rick Perry.

We’ll see if Trump has developed that politician’s sense of risk. If he goes too far, one or certainly two more equivalents of “Mexican rapists,” it’ll be open season on him. He’s at a point of maximum leverage right now, and if he wants to stay there, he’s got to tuck it in about 10 or 15 percent and start employing the kind of racialized euphemisms that are not only tolerated but celebrated within the Republican Party—build the damn fence, no amnesty, al Qaeda is storming the mainland through Obama’s porous border, etc. That way, he’ll hang around. And he’ll build enough of a following that the threat of a viable independent candidacy remains a real one. And that is Trump’s trump card. And it makes Reince Priebus a very nervous man.