An essay by Thomas Carothers, Director of Carnegie’s Democracy, Conflict, and Governance Program. From the introduction:

[A]s the health of U.S. democracy has become a matter of serious concern, the question of democracy’s relationship with national power arises in the United States itself. Specifically, how is the degradation of democracy at home affecting or likely to affect U.S. power abroad?

Given the uncertain endpoint of America’s current democratic decline, no definitive answer to this question is yet available. But a look at the main contours of the current U.S. democratic backsliding should raise concerns about how the erosion of the nation’s democratic foundations may diminish its national power. Although President Donald Trump and his administration are a significant part of the story of America’s current democratic woes, the analysis in this essay is not an account of how Trump’s foreign policy is changing U.S. power. The analysis concentrates on those elements of U.S. democratic backsliding—some of which are directly tied to Trump and some of which are not—that appear to be affecting U.S. power.

And the conclusion:

Is the damage to U.S. power reversible? Some of the damage will be quick to break, slow to fix. Renewing the attractiveness of U.S. democracy as a political exemplar is likely to be very slow, even if favorable democratic developments occur down the road. The same is true of rebuilding the bureaucratic capacity needed to ensure that policies are informed by deep expertise. Moreover, even if the centralization and personalization of power occurring now are substantially reversed in the years ahead—a tall order—it seems probable that the severe polarization afflicting the U.S. political system and society will continue, given that its roots are much deeper than the current administration. As a result, the problems that it causes for U.S. power—like the lurching between discordant policies and the attendant effects on the U.S. reputation as a reliable, trustworthy partner—are likely to continue for an extended time.