(CNN)Donald Trump quipped during Sunday night's debate that if he were president, Hillary Clinton would be in jail.
Trump threatened to jail Clinton if elected. These countries might do the same.
The comment caught many Americans off-guard. And it sounded disappointingly familiar to those living under authoritarian regimes.
To start, here's what Trump said: "I hate to say it, but if I win, I am going to instruct my attorney general to get a special prosecutor to look into your situation (Hillary Clinton's email scandal)."
When Clinton responded by saying it's good that someone with Trump's temperament isn't in charge, he interjected, "because you'd be in jail."
So why did the comment elicit such passionate responses from both Republicans and Democrats?
Trump supporters argue that if Clinton was not a well-known politician, she very well may have been charged and faced jail time for using a private email server for official business while secretary of state.
The FBI investigated and concluded there was not enough evidence to merit a criminal prosecution before handing over its findings to the US Department of Justice.
But Americans of all stripes consider the peaceful handover of power to political opponents one of the most demonstrable symbols of the country's healthy democracy.
Here are some other leaders and countries that have jailed political opposition while in power.
Vladimir Putin is often accused of jailing his political opponents. A prominent example: Mikhail Khodorkovsky, a former oligarch and Putin opponent, spent 10 years in prison on charges many believe were politically motivated. He now lives in exile in Switzerland.
Leopoldo Lopez, an opposition leader in Venezuela, is serving a 14-year prison sentence on charges that a former prosecutor says were fabricated by the government.
Taiwan's former president, Chen Shui-bian, was jailed on corruption charges that he says were politically motivated after his political party lost power in 2008.
Augusto Pinochet assumed power in Chile after a coup in 1973, disappearing and arresting political opponents.
North Korea has executed its top education official and defense minister in the last two years.
And an entire wing of the notorious Evin prison in Iran is believed to house political prisoners.
That's just a snapshot of the cases around the world in recent history, but the point is this -- many Americans believe jailing political opponents, or threatening to, is the hallmark of a dictatorship, not a vibrant democracy.
And that's a view shared by Democrats and Republicans.
Ari Fleischer, President George W. Bush's press secretary, said Trump was wrong.
David Frum, a prominent neoconservative, tweeted "Who would consent to serve as Attorney General to a president who believed he could direct prosecutions of his political opponents?"
And former Attorney General Eric Holder also said that jailing Clinton would constitute an abuse of his power.
"You cannot underestimate the history was made in our country. A line was crossed that I don't know has been crossed in my lifetime, maybe ever. He threatened to jail his opponent," CNN political commentator Van Jones said.
He went on to call it a "new low in American democracy."
Said CNN's Dana Bash: "Not to sound too corny, but what makes this country different from countries with dictators in Africa or Stalin or Hitler or any of those countries with dictators and totalitarian leaders is when they took over, they put their opponents in jail.
To hear one presidential candidate -- even if it was a flip comment, which it was -- say you're going to be in jail to another president on the debate stage in the United States of America. Stunning. Just stunning."