Despite a divisive presidential campaign, there are still a minority of voters who are undecided. For some of these voters, the debate between Hillary Clinton and Donald Trump on Sunday didn't sway them toward either candidate.

Debates don't usually make a difference in polling since most people vote along party lines, said American politics and voter behavior expert Justin Holmes. In such a "high-profile and polarizing" election, Holmes said, he is shocked that "there would be anybody left who is left undecided."

The town hall debate enabled undecided voters to ask the candidates questions about their plans for office. With the election about four weeks away, polls show some people are still undecided. For example, on Monday a NBC/Wall Street Journal poll found that Clinton was leading with 45 percent of the vote, Trump with 35 percent of the vote and 4 percent of voters were undecided.

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Closer to home, Tasha Scott, a representative for transportation services in the San Bernardino school district isn't sure who she will vote for. Trump's performance on Sunday didn't appeal to her. She said, "I think he's just one big joke. Everything that has come out his mouth is B.S. He's a hypocrite."

Scott said she was also turned off from Clinton because she believed she is an "emotional female who has her husband in her ear."

The debate wasn't helpful to Scott.

"I feel like it's a giant circus, these debates … I don't think that in the end I'm going to end up voting because I personally don't want to be responsible for helping him or her get into office."

The debate also wasn't helpful to Denise Lugo, who works at a gym and is undecided.

"It's really hard. None of them are saying what they are doing for the country. They just kept pointing out stuff about each other," she said.

But still if there was any debate that might have the ability to make a difference for voters, it would be this one, said Holmes, an assistant professor of political science at the University of Northern Iowa.

"Generally speaking, when we see debates you have two people who are generally evenly matched. The discrepancy between them are not real big. It's fairly ambiguous who is the winner. We are seeing a much bigger different match-up this time."

Holmes said the bar was so low for Trump's performance that he was expected only to not make the situation worse. Trump was appearing with Clinton for the first time since the leaked recording on Friday where he bragged about groping women and grabbing a woman's genitals without her permission.

At the debate, Trump brought women to sit in the audience who claim they were sexually assaulted by Bill Clinton in what Holmes called "a bold move." Holmes said that it may remind Republicans of how much they dislike Clinton but wouldn't do much to convince moderates.

But it wasn't enough to quell concerns of some prominent Republicans. On Monday, Paul Ryan said he would no longer defend Trump.

Holmes said he isn't sure that Trump's performance will do anything to pull independents "off the fence." He thought that Clinton may have done better swaying independents by showing that she is somebody who can present herself as a person who can "calmly, poignantly talk about policy."

Holmes said the biggest takeaway from the debate that it was just the "nastiest, most unpleasant debate ever."

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