On the eve of its national convention this week, the Republican Party decided not to adopt a new platform for 2020. In so doing, it ended an unbroken tradition dating back to 1856, when the first Republican convention committed itself to opposing slavery, supporting the admission of Kansas as a free state, and building a railroad to the Pacific Ocean. The GOP produced 41 platforms in the ensuing 164 years, but there will be no 42nd one this year.

By itself, the decision to forgo a new party manifesto isn’t the worst thing in the world. Platforms have no discernible impact on voters, and candidates don’t consider themselves bound by their party’s formal statement of positions and beliefs. In 1996, Bob Dole bluntly let it be known that he hadn’t even read the GOP platform. And when Mitt Romney disagreed with the abortion plank in the 2012 platform, the party’s chairman downplayed the breach: “This is the platform of the Republican Party; it’s not the platform of Mitt Romney.” Platforms may be useful documents for historians tracing a party’s ideological shifts over time, but in electoral terms, they stopped mattering decades ago.

In a resolution adopted Sunday, the Republican National Committee said there would be no new platform because pandemic-related restrictions made it too difficult to bring delegates together to draft one. If only the party had left it at that.

But the resolution didn’t stop there. It went on to dismiss platforms as cynical documents that shouldn’t be taken seriously anyway. “Parties abide by their policy priorities,” the resolution declared, “rather than their political rhetoric.” Yet rather than list even a few of the GOP’s 2020 policy priorities, party leaders summarized their outlook in a single principle:

“The RNC enthusiastically supports President Trump… . The Republican Party has and will continue to enthusiastically support the President’s America-first agenda … [and] calls on the media to engage in accurate and unbiased reporting, especially as it relates to the strong support of the RNC for President Trump and his Administration.”

This is a remarkable and disturbing document.

The transformation of the Republican Party into a vehicle propelled above all by loyalty to Donald Trump has been obvious since 2016. But for a party to eschew the adoption of a platform in order to proclaim its fealty to one man is something new in American politics. The RNC resolution is an official declaration that the Republican Party’s singular purpose is Trump’s reelection — period. There are no core values or philosophical convictions that matter more. What Republicans stand for is whatever Trump stands for. And since Trump himself can’t articulate what he stands for, what use has the GOP for a formal platform?

If the Republican Party hasn’t become a full-on cult of personality yet, it is marching briskly in that direction. Of the more than 600 TV commercials broadcast in Republican primaries this year, Politico reports, more than 60 percent have featured Trump’s name or likeness. “Adherence to Trump,” the story said, “has quickly surpassed taxes and spending as the most dominant issue to Republican primary voters.” During the GOP convention’s roll call of the states on Monday, Montana’s Republican chairman dubbed his state “Trumptana.” A Fox News graphic depicted 12 “Republican National Convention Key Speakers”; six were members of the Trump family.

To be fair, the Republican and Democratic parties have routinely associated themselves with their presidential nominees, and it is normal for presidents to leave their stamp on their party’s philosophical creed. Ronald Reagan’s muscular internationalism and free-market optimism shaped the GOP’s idea of itself in the 1980s, so it was only to be expected that Trump’s populist nationalism and hostility to free trade would influence the meaning of Republicanism in this decade. But there is nothing routine about a party’s national committee openly and proudly announcing that it exists for no purpose other than supporting the president and his agenda, whatever that agenda turns out to be.

Unquestioning support for the supreme leader is not a democratic value, as Republicans emphasized just four years ago. In its 2016 platform, the Republican National Committee blasted Barack Obama and the Democrats for having “changed what John Adams called ‘a government of laws and not of men’ into just the opposite.” This year there is no platform. There is only a resolution “enthusiastically” and “unanimously” endorsing whatever Trump wants. What would John Adams have called that?

(Jeff Jacoby is a columnist for The Boston Globe).