Democratic freedoms are under attack in the United States because of the actions of President Trump, threatening to hasten the retreat of democracy around the world, according to a report released Monday by Freedom House.

In a signed essay within the report, Freedom House President Michael Abramowitz accused Trump of undermining the pillars of freedom, including separation of powers, a free press, an independent and impartial judiciary, and the legitimacy of elections.

Abramowitz acknowledged that American freedoms have been eroded under previous administrations.

“At the midpoint of his term, however, there remains little question that President Trump exerts an influence on American politics that is straining our core values and testing the stability of our constitutional system,” he wrote. “No president in living memory has shown less respect for its tenets, norms and principles.”

The report comes a month after another watchdog group, Transparency International, said in its annual Corruption Perceptions Index that threats to the American system of checks and balances had knocked the United States out of the top 20 “cleanest” countries.

Among the dozens of groups that issue indexes measuring the principles of democracy, Freedom House is considered the most authoritative. It has rated countries on political rights and civil liberties since 1973, assessing them in three categories as “free,” “partly free” or “not free.”

Its annual “Freedom in the World” report is routinely cited in foreign policy discussions, and its advice is weighed in determining U.S. government grants through the Millennium Challenge Corporation.

In the newest report, the United States lags behind 51 countries, in the middle of a basket of 87 countries categorized as free. Less than a decade ago, it ranked behind just 30 countries. Now, the United States is outpaced by other big democracies such as Canada, Britain and Germany, and on the same level as Belize, Croatia, Greece, Latvia and Mongolia.

Among the measures Freedom House uses to assess rights is the extent that a country’s elections are free and fair, political pluralism and participation. Civil liberties are measured by markers such as free and independent media, freedom of expression and assembly.

On a 100-point scale, the United States was given a score of 86, a decline of eight points since 2010. Although this year’s overall score is unchanged from last year’s, that is only because widespread protests for social change and against government policies bumped up the points for freedom of assembly. That, in turn, offset a drop in ratings for equal treatment before the law, due to the administration’s policies on asylum seekers and refugees.

The report notes the decline in American democracy under previous presidents. It mentions the National Security Agency’s telephone-metadata collection instituted under George W. Bush after the 9/11 attacks and the Obama administration’s prosecution of media leaks under the Espionage Act.

Abramowitz said in an interview that it was important to single out the decline of freedoms in the United States because the annual report has tracked the retreat of democracy around the world for 13 consecutive years. Several countries that embraced democracy after the collapse of the Soviet Union are backsliding. And the United States, traditionally an exemplar and advocate for democracy and human rights, is now at what Abramowitz said is an inflection point.

“Yes, our institutions are resilient,” he said. “Yes, our democracy is very strong. But we can’t assume this will continue, absent a really aggressive effort by leadership to push back against democratic decline. It’s kind of a wake-up call.”

In the essay titled “The Struggle Comes Home: Attacks on Democracy in the United States,” Abramowitz cites a litany of Trump actions. Among them are Trump’s feuds with allies, his attacks on the media as the “enemy of the people,” his resistance to anticorruption norms and his unfounded claims of voting fraud.

“But the most glaring lapse is the president’s refusal to clearly acknowledge and comprehensively combat Russian and other foreign attempts to meddle in American elections since 2016,” he wrote.

He lauds key institutions that have pushed back, including the judiciary and the media, and the number of large protests and large voter turnout for the midterm elections.

“We cannot take for granted that the institutional bulwarks against abuse of power will retain their strength, or that our democracy will endure perpetually,” he wrote. “Rarely has the need to defend its rules and norms been more urgent.”