The global impact of a Donald Trump presidency would be disastrous.
But even a Hillary Clinton win won't help reverse the worldwide retrenchment in democracy and human rights unless she brings a change in policy from the current administration.
If all of that strikes you as a bit too breathless, consider what's happened over the past decade.
The leading authoritarian powers of the world - China, Russia and Iran - have tightened the screws at home while becoming far more aggressive beyond their boundaries. They have proven that the internet, contrary to earlier expectation, can be turned into a weapon of control. They have proven, again contrary to earlier assumptions, that a country can enter the global economy while squelching free speech, worship and assembly at home. They have formed a loose dictators' alliance, working together to undermine and discredit the principles of liberal economics and individual rights.
Clinton attacks Trump over campaign team restructuring
Meanwhile, nations that were assumed to be safely in the camp of democracies, including many U.S. allies, have slipped toward authoritarianism. In some, such as Thailand, reversion has come through old-fashioned military coups. In others - Poland, the Philippines, Hungary, Turkey, Nicaragua - elected governments are undoing the protections of democracy.
Still other nations, soft authoritarians that had promised greater openness, have unapologetically gone the other way: Egypt, Ethiopia, Bahrain, Malaysia, to name just a few.
Freedom House, the nonprofit organization that has been keeping track of these things since Eleanor Roosevelt helped found it 75 years ago, has the dismal numbers. Over the past decade, the level of freedom has declined in 105 countries and advanced in only 61, the group says - and last year was the worst yet, with 72 nations losing ground. Around the world, "press freedom declined to its lowest point in 12 years in 2015," it reports.
Trump would stoke the dictators' momentum in at least three ways. Most obviously, just the fact of his presidency would serve as a four-year indictment of the democratic system. If an unqualified bigot could rise to the top of the world's oldest democracy, how could Freedom House or anyone else plausibly urge other nations to adopt our system of government?
Trump also would undermine democracy abroad by virtue of his disrespect for democratic norms at home. He has endorsed torture and other illegal acts of war, disparaged freedom of the press, undermined a free judiciary, campaigned by invective rather than debate and warned critics that they will suffer if he is elected. And if all that is not enough to give comfort to authoritarian rulers with similar values, Trump has expressed open admiration for the world's worst thugs, from Russia's Vladimir Putin to the butchers of Tiananmen Square.
Trump vows to crack down on undocumented immigrants
Even if he loses, of course, democracy's reputation will have taken a hit: How could such a man have become a major party nominee? But perhaps another story line will emerge, too: Even in times of economic dislocation, even faced with an alternative that many voters disliked, Americans were too wise to let the worst befall them.
But a Clinton presidency will shift the global momentum only if she adopts goals that President Obama enshrined as a candidate but largely abandoned as president.
Of course global trends rest on many factors, of which U.S. leadership is only one. But when he was campaigning, Obama cited as models Franklin D. Roosevelt, Harry Truman and John F. Kennedy - who ensured, he wrote in the magazine Foreign Affairs, that America "stood for and fought for the freedoms sought by billions of people beyond our borders." He said his administration would work toward "building just, secure, democratic societies" where citizens could "choose their leaders in climates free of fear."
But democracy promotion faded as a goal once Obama moved into the White House. In negotiations with China, Iran, Cuba and North Korea, human rights were never a priority. He apologized to Argentinians for America's Cold War acceptance of its "dirty war," but overlooked similar or worse abuses in anti-terror allies such as Egypt, Ethiopia and Saudi Arabia. He hoped that setting a good example at home - ending torture, closing (as he hoped to do) Guantanamo - would resonate overseas, but the results were disappointing.
How far the administration evolved from Obama's 2007 vision can be measured in an article by Vice President Joe Biden in the current issue of the same magazine that barely mentions democracy or human rights. Biden sets tasks for the next administration to achieve a "more peaceful and prosperous future," none explicitly related to freedom: deepening alliances in Asia and the Western Hemisphere, addressing climate change and terrorism, improving ties with regional powers.
Those are all important. But they will all be far more elusive if democracy continues to dwindle away.
Fred Hiatt is the editorial page editor of The Post. He writes editorials for the newspaper and a biweekly column that appears on Mondays. He also contributes to the PostPartisan blog.