Hillary Clinton delivered a fiery speech before a few thousand supporters on Sunday night, during which she accused her Republican opponent of "denigrating America for decades" and posing a direct threat to democratic process.

"I want to make this serious point," the Democratic presidential hopeful told the crowd gathered at the University of North Carolina in Charlotte. "Some of you know people who will vote for [Donald] Trump. I want them to know, I want to be the president for every American – Democrats, Republicans, independents."

"We have to bring this country together. We have to have everyone pulling in the same direction. I understand some people are angry, but anger is not a plan," she said.

Clinton spent a significant portion of her speech characterizing Trump as unfit to be president. The GOP nominee has spent a lifetime lobbing insults at politicians and contributing to the growing division that has alarmed many Americans.

"Donald has been denigrating America for decades," Clinton said. "It didn't start with me. It didn't start with President Obama."

"Back in 1987, he spent $100,000 on an ad in the New York Times criticizing President Reagan," she recalled. "He just loves to criticize and loves to insult, but we need people to actually come together and find common ground."

The former first lady said she has had her fair share of differences "on policies and principles" with political opponents and former presidents, but never questioned their fitness to lead the country like she does when it comes to Trump.

"This is not like anybody else who's ever run for president who has demonstrated unequivocally that he is unqualified and unfit to be president and commander-in-chief of the United States of America," she said to applause.

Trump has drawn criticism from across party lines recently for pledging only to accept the outcome of the Nov. 8 election if he wins. He was first asked about the election results and peaceful transition of power during the final presidential debate last week.

"I assumed he would say, 'of course,'" Clinton told the crowd, referring to moment in which Trump was asked by debate moderator Chris Wallace if he would accept the results of the election regardless of the outcome.

Trump's refusal to do make the pledge demonstrates that he is "a direct threat to our democracy," said the Democratic nominee.