Three years into the Trump administration, American democracy has eroded to a point that more often than not leads to full-blown autocracy, according to a project that tracks the health of representative government in nations around the world.

The project, called V-Dem, or Varieties of Democracy, is an effort to precisely quantify global democracy at the country level based on hundreds of indicators assessed annually by thousands of individual experts. It’s one of several ongoing projects by political scientists that have registered a weakening of democratic values in the United States in recent years.

V-Dem’s findings are bracing: The United States is undergoing “substantial autocratization” — defined as the loss of democratic traits — that has accelerated precipitously under President Trump. This is particularly alarming in light of what the group’s historic data show: Only 1 in 5 democracies that start down this path are able to reverse the damage before succumbing to full-blown autocracy.

“The United States is not unique” in its decline, said Staffan I. Lindberg, a political scientist at Sweden’s University of Gothenburg and a founding director of the project. “Everything we see in terms of decline on these indicators is exactly the pattern of decline” seen in other autocratizing nations, like Turkey and Hungary, both of which ceased to be classified as democracies in recent years.

Each year, the V-Dem project asks its experts to rate their respective nations on hundreds of measures of democracy, such as the presence of legislative checks on executive power, freedom of personal expression, the civility of political discourse, free and open elections, and executive branch corruption, among others.

The United States is backsliding on all of those measures. “Executive respect for the Constitution is now at the lowest level since 1865,” said Michael Coppedge, a Notre Dame political scientist and one of the project’s chief investigators. “Corruption in the executive branch is basically the worst since Harding.”

Warren G. Harding, whose administration was tainted by corruption and scandal, is routinely ranked among the nation’s worst chief executives.

Trump, for instance, has repeatedly floated the idea of staying in office longer than the constitutionally mandated two terms. The businesses he owns have profited from repeated presidential visits, and federal courts are currently weighing whether he has violated the Constitution’s prohibition against accepting payments from foreign governments. And several current and former members of his inner circle — including Stephen K. Bannon, Paul Manafort and Roger Stone — have been arrested or indicted since he took office.

Brendan Nyhan, a political scientist at Dartmouth College, said that “experts rate U.S. democracy as getting worse on average,” but there are considerable differences in “how they characterize the severity of the decline we’ve experienced and what they expect in the future.”

Nyhan says he is most concerned about Trump’s repeated attacks on the integrity of U.S. elections. Trump recently said that “the only way we’re going to lose this election is if the election is rigged,” for instance, and habitually casts vote-by-mail efforts as inherently fraudulent. Both beliefs are false.

Nyhan is co-director of Bright Line Watch, a group that routinely surveys hundreds of political scientists to issue periodic assessments of the health of democracy in the United States. Those assessments show a post-2016 decline in democratic performance similar to V-Dem’s data.

“Democracy depends on both sides accepting the results of free and fair elections and willingly turning over power to the other side if they lose,” Nyhan said. “We’ve never had a president attack our electoral system in this way.”

Lindberg refers to presidential attacks on the pillars of democracy as “dictator drift,” and says it’s a common feature of authoritarian leaders around the world.

“That’s Erdogan in Turkey,” he said. “That’s Lukashenko in Belarus. That’s Orban in Hungary. That’s a slew of African dictators.”

He’s concerned about the rise of a sort of “sultanistic” power structure in the GOP, where the party largely abandons its core principles to support whatever the leader wants. The telltale sign of that, he said, was the GOP’s decision to not create a 2020 platform. Instead, it issued a resolution saying, among other things, that “the Republican Party has and will continue to enthusiastically support the President’s America-first agenda.”

“They just line up behind Trump,” Lindberg says. “That should ring some serious alarm bells. You have a sort of head of a family clan, without a program other than ‘we support this person.’ ”

Coppedge is particularly concerned about the possibility of election-related violence. “What I most worry about is a scenario with the incumbent president declaring victory before all votes are counted, and his followers believing any additional mail-in ballots are invalid and taking to the streets.”

“I do think there is going to be some election violence,” he added, “and I hope it won’t be widespread or long-lasting."

Lindberg is also deeply troubled by the president’s history of endorsing violence against his perceived political opponents. “This is the precursor of civil war,” he said. “Imagine that Trump loses by a margin that’s not convincing to all his supporters. He refuses to leave the office and encourages his supporters to ‘go out and defend the Constitution.' ”

Nyhan says that while these “worst-case scenarios remain unlikely,” we are in “unprecedented times” and should “remain vigilant.”

Coppedge recommends people concerned about these outcomes get involved in the electoral process to help make things better. “Volunteer to become a poll worker, or help some get-out-the-vote effort, or work with a political party to encourage turnout to make sure your side wins by a clear margin,” he said.

“I think that the chances are in the medium term, the long run things are going to work out,” he said. "But I think it’s going to be a bumpy ride between now and January.”

Lindberg is less optimistic.

“If Trump wins this election in November, democracy is gone” in the United States, he says. He gives it about two years. “It’s really time to wake up before it’s too late.”