Republican presidential nominee Donald Trump and Democratic presidential nominee Hillary Clinton during the second presidential debate, held Sunday at Washington University in St. Louis. (The Minnesota Star Tribune)

Anyone who saw Donald Trump's boast of his celebrity-bestowed ability to indiscriminately grab women by the genitals as a new political low was proved wrong by Sunday's debate.

That's when the Republican nominee hit a frightening nadir in American politics by saying on live television that if he became president, his opponent, Hillary Clinton "would be in jail." There is, and can be, no normalizing of such statements. This country doesn't make political prisoners of rivals. Part of democracy's hope and promise, and what has always set the U.S. apart from so many other countries, is the peaceful transition of power every four years. Opponents here are defeated, not imprisoned.

This was no "quip," as the campaign has tried to say in the aftermath of a debate that should put the final nail in the coffin of the most disgraceful presidential campaign in U.S. history. Chants of "lock her up" have become staples of Trump rallies, egged on by the candidate himself. Minnesota's own Republican Party, at its State Fair booth, featured a cutout of Clinton in a black-and-white-striped prison uniform. State Party Chairman Keith Downey characterized it as "having a bit of fun." Trump, whom the Star Tribune Editorial Board has urged to leave the race, is creating dangerous expectations here that could persist well past November.

Trump's performance throughout the debate was an insult to voters. After praising Russian leader Vladimir Putin for months and having done business with Russian oligarchs for decades, Trump on Sunday professed to know nothing about Putin or Russia, just that he thought it would be "nice" if the U.S. were friends with the nation it has formally accused of attempting to interfere in the presidential election.

Trump dismissed the vulgar tape of him describing sexual assault as "locker room talk" that was embarrassing, but of no consequence. He may be surprised to find out that many women — and men — disagree. He brazenly admitted that he used a nearly $1 billion loss to escape years of taxes and boasted of a tax plan that studies show would greatly benefit the wealthy at the expense of everyone else.

He continued to repeat the lie that he opposed the war in Iraq and again attempted to blame birtherism — his yearslong attempt to delegitimize the nation's first black president — on Clinton, whom President Obama wholeheartedly supports. Even more despicable was Trump's blatant attempt to distract from his own misdeeds by going after Clinton for the sins of the husband who cheated on her. If that wasn't enough, Trump left his spot several times during the debate to strut to Clinton's side, standing behind her, glowering as she spoke.

The Trump campaign has devolved into a series of lies, deflections and dog whistles, and appears to be spiraling further downward as his desperation mounts. And yet, some Republican leaders who claimed outrage at the tapes, professed themselves to be satisfied, even proud, of Trump's debate. It's hard to imagine a bar set so low that such a performance could clear it.

Voters should not delude themselves. Trump, like other demagogues before him, is telling the country plainly what it can expect from a Trump presidency. It is a frightful picture of things to come.