The much-ballyhooed “loyalty pledge” that the Republican National Committee demanded Donald Trump sign was supposed to “box in” Trump, leaving him no way of running as a third-party candidate if he fails to win the GOP nomination.

Trump announced Thursday that he had signed the pledge. Surely that is not an entirely insignificant get for Republican leaders — it makes it perhaps marginally less likely that Trump will launch a third-party bid.

But it would not be at all surprising if Republican primary voters see this in strikingly different terms than the party’s leaders intended.

They may think Trump bent the Republican establishment to his will, rather than the other way around.

Here’s what Trump said, according to CNN: “The best way for the Republicans to win is if I win the nomination and go directly against whoever they happen to put up. And for that reason, I have signed the pledge.”

Trump added: “I will be totally pledging my allegiance to the Republican Party and for the conservative principles for which it stands.”

When Trump was asked what he got in return for signing the pledge, he replied, “Assurance that I will be treated fairly.”

The story line is now that Trump and the Republican establishment have reached an understanding, after GOP leaders agreed to stop treating him unfairly.

Trump said the GOP has been “terrific” to him (he does love that word) because he insisted on that treatment.

He — not Republican leaders — set the agenda.

Even if the notion that Trump was ever treated unfairly is absurd, is there any reason to doubt that a whole lot of Republican primary voters will be very receptive to this interpretation of what happened?

We keep hearing that Trump’s surge is rooted in the fact that a lot of Republican voters are very angry with the party’s leaders, because they’re feckless and ineffective.

Those voters think Trump would bang heads together and accomplish what they can’t or won’t.

Surely a lot of these voters are also happy to believe that said feckless and ineffective Republican leaders want Trump to disappear not because he risks destroying the GOP brand among Latinos but because he’d disrupt their cozy Washington arrangement in which they aren’t willing to do what it takes to stop President Barack Obama.

That’s why they’ve been treating Trump unfairly!

By threatening a third-party candidacy, Trump forced the party leaders’ hand.

As a special bonus, Trump also gets to define what “fairly” means.

If at any time in coming weeks and months, Trump even so much as hints that Republicans are treating him unfairly, mass panic will again set in.

That will occur without anyone even knowing by what objective metric “fair treatment of Trump” by the party can even be gauged.

OK, I don’t know for sure how Republican primary voters will react to this whole thing.

But Trump has proved astoundingly adept at growing the ranks of his supporters by broadcasting coded messages of all kinds — messages that have hit their marks, and then some.

This might not prove to be an exception.

Greg Sargent is a columnist for The Washington Post.