Democracy is in under siege around the world, according to a new report by the Economist Intelligence Unit.

The annual Democracy Index tracks the health of the world's governments. And the results for 2017 are depressing. In 89 countries, democratic norms look worse than they did last year, the report's authors write. Just 4.5 percent of the world's residents live in fully functioning democracies, down from 8.9 percent in 2015.

That precipitous drop is thanks, primarily, to the United States. In 2016, the Economist demoted the country from a "full" to "flawed" democracy, citing a "serious decline" in public trust in U.S. institutions. In 2017, the United States didn't fare any better, retaining its same rank and score. As the report's authors explain, President Trump was able to tap into the disempowerment felt by voters, who are frustrated with U.S. political and economic stagnation.

Yet Trump's presidency has only further polarized the country, the authors say. Americans remain far apart on issues such as immigration and economic and environmental policy. "The growing divisions between (and within) those who identify as Republicans and Democrats help to explain in part why the Trump administration is finding it so hard to govern, despite controlling both houses of Congress," they write.

President Trump gave his first State of the Union address to Congress on Jan. 30. Here are the highlights from his remarks. (Jenny Starrs/The Washington Post)

The report's authors caution that this polarization foreshadows further democratic deterioration, particularly because polarization leads to a less functional government, one less able to compromise and come together to solve big issues. The trend toward partisanship is also tied to a shift in confidence in government.

Across the world, democratic norms are being eroded. Symptoms include curbs on freedom of speech, declining trust in institutions, a drop in popularity of mainstream political parties and erosion of civil liberties. A third of the world's population lives under authoritarian regimes.

The world's most democratic countries include Norway, Iceland, Sweden, New Zealand, Denmark, Ireland, Canada, Australia, Finland and Switzerland. Other major European countries — such as Britain and Germany — round out the list of "full" democracies. Only one country from the developing world, Uruguay, is represented.

Among the world's most authoritarian places are North Korea, Syria, Congo and Chad.

Spain's democratic bona fides suffered as a result of its attempt to stop Catalonia's independence referendum by shuttering polling stations, closing down websites and policing voters. In Eastern Europe, most countries performed even worse on the democracy index than usual, thanks to the rise of strongmen.

The report's authors do find some cause for hope. "If 2016 was notable for the populist insurgency against mainstream political parties and politicians in the developed democracies of Europe and North America," they write, "2017 was defined by a backlash against populism." Among the examples they include: a grass-roots effort to reverse Brexit and opposition to Trump.