PITTSBURGH - With Donald Trump remaining coy about his willingness to accept an election outcome that doesn't include his winning, Democratic candidate for president, Hillary Clinton, is calling his stance a threat to American democracy and possibly a sign of worse things to come.

"Trump refused to say he would respect the result of this election," Clinton told a crowd here on Saturday.

"Make no mistake about it, folks: He is threatening our democracy."

Trump first refused to say whether he'd accept defeat at the polls in Wednesday's presidential debate, later explaining he suspects the election may be rigged by Democrats using voter fraud or vote rigging against him.

"I'll keep you in suspense," he quipped when posed the concession question by moderator Chris Wallace.

Since then, much has been made of his apparent unwillingness to accept any unfavorable outcome, with his critics calling the peaceful transition of power a hallmark of American democracy, and Trump's refusal to embrace it both un-American and despotic.

"I've lost elections and you don't feel very good the next day," Clinton said, picking up there. "But we know the difference in our country between leadership and dictatorship. ... Both Trump and I should be grateful for the opportunities our country has given us."

Clinton also pointed to Trump's vow to investigate and possibly jail her if elected, saying, "When Trump says he wants to jail his opponent, and that means me, I say to myself, 'We don't do that in America.' We actually have courts and laws and an independent judiciary."

Trump made the vow in another presidential debate, and took similar flack from critics who called the use of executive power to investigate and imprison a political opponent shocking and dictatorial.

But most of all, Clinton said Saturday that she was glad the debates which spawned all of these claims, vows and accusations were finally over.

"That was the third and last time I will ever have to debate Donald Trump," she said of Wednesday's showdown.

"I have now spent four-and-a-half hours on stage with Donald. Proving once again I have the stamina to be president."