One of the most talked about moments from Sunday's Presidential debate in St. Louis may well have been when Donald Trump all but vowed, if he is elected in November, that he will try to send Hillary Clinton to prison for the way she handled her private email server while Secretary of State.

"If I win, I'm going to instruct the Attorney General to get a special prosecutor to look into your situation, because there's never been so many lies, so much deception," Trump said.

"There has never been anything like this, where e-mails and you get a subpoena and after getting the subpoena, you delete 33,000 e-mails," he added about Clinton's email troubles.

When Trump's time ended on that question, Clinton accused him of peddling a story that was "absolutely false."

"It's just awfully good that someone with the temperament of Donald Trump is not in charge of the law of our country," Clinton said.

"Because you'd be in jail," Trump shot back, in what was one of the most memorable moments of the debate.

And it seemed to play well with a voter panel put together by Frank Luntz:

But while Trump's threat to immediately appoint a special prosecutor to put Clinton in jail was a big winner with many of Trump's supporters, it left others with their mouths agape.

"If you don't think Trump wants to mirror Putin as President, then you didn't hear him threaten to jail his political rival if elected," said Sen. Chris Murphy (D-CT).

"Only in Third World countries do political candidates threaten to throw their opponents in jail," said Dan Pfeiffer, a former top aide to President Obama.

"Winning candidates don't threaten to put opponents in jail," said Ari Fleischer, White House Press Secretary to President George W. Bush.

"What Trump has suggested is straight out of a dictator's handbook," said former Clinton aide Paul Begala.

But for many Trump supporters, it's a common sense line by Trump - just think of the "LOCK HER UP!" cheer that is commonplace at a Trump rally.

There was no immediate reaction from Republican lawmakers in the Congress, as only a handful of them even showed up on Twitter to react to the second debate.

One would expect Trump to keep after Clinton today when he makes two stops in Pennsylvania; Clinton is in Ohio.