Here are key moments from the third and final presidential debate between Democrat Hillary Clinton and Republican Donald Trump, Oct. 19, in Las Vegas. (Sarah Parnass/The Washington Post)

LAS VEGAS — During the final presidential debate, Hillary Clinton accused Donald Trump of inciting and encouraging violence at his campaign rallies, which she said is un-American. Trump responded by accusing Clinton of causing that violence.

Earlier this week, two Democratic political operatives left their jobs following video investigations by James O'Keefe's Project Veritas Action that showed them entertaining dark notions about how to win elections. One of the operatives bragged about interrupting Republican rallies — which Trump has used as evidence that the violent clashes that often break out at his rallies are the work of Clinton and Democrats.

Questions are being raised about edited undercover excerpts of Democratic political consultants, which were released by conservative activist James O'Keefe's group Project Veritas Action. (Jenny Starrs/The Washington Post)

Clinton's comment came after she listed controversial comments that Trump has made about women, the disabled and veterans.

"This is a pattern, a pattern of divisiveness of a very dark and, in many ways, dangerous vision of our country where he incites violence, where he applauds people who are pushing and pulling and punching at his rallies. That is not who America is."

"It's so sad when she talks about violence at my rallies — and she caused the violence," Trump responded. "It's on tape."