The slow, steady erosion of democracy around the world continued for the 13th consecutive year, according to the latest annual "Freedom in the World" report by Freedom House, a watchdog group that advocates for democracy and human rights.

The big picture: Between 1988 and 2005, democracy surged around the world. Since then, the reversal has been less dramatic, but it has been "consistent and ominous," according to the report.

Political rights and civil liberties became weaker in 68 countries since last year's report, and improved in only 50 countries.

became weaker in 68 countries since last year's report, and improved in only 50 countries. The authors cite a shifting global balance of power in favor of countries like China, and "anger and anxiety in Europe and the United States over economic inequality and the loss of personal status" as underlying causes of the strains we're seeing on democratic institutions.

a shifting global balance of power in favor of countries like China, and "anger and anxiety in Europe and the United States over economic inequality and the loss of personal status" as underlying causes of the strains we're seeing on democratic institutions. Globally, 39% of people live in countries deemed "free," while 24% live in "partly free" countries and 37% "not free."

A warning about the United States: The report says the U.S. freedom score has declined by 8 points (from 94 to 86) over the past eight years. It's still firmly in the "free category," but it's falling behind counterparts like the U.K., Canada, France, Australia, Germany and Japan.

The report blames longstanding problems like political polarization, loss of economic mobility, the influence of special interests and the rise of partisan media. But it also warns that President Trump "exerts an influence on American politics that is straining our core values and testing the stability of our constitutional system."

Other big changes: