Witnesses said McCain-Palin supporters pulled up one heckler by his hair and punched another, ABC News affiliate KNXV reported.
An exclusive KNXV video clip shows one man -- who on the tape declares himself a libertarian opposed both to McCain and President Obama -- shouting "freedom of speech" as he's dragged outside, tackled and handled roughly by multiple people, including one in a McCain T-shirt.
"What are you doing to me? Help me," the man yells as police race up, grab him and pull him away, still screaming. "Get off me. Freedom of speech, dammit. What's your guys' problem?"
"You're a douche, that's our problem," an unidentified woman says.
Despite Palin's popularity with some groups, not everybody is a fan of hers, either.
A new Washington Post Poll found that although she is hugely popular among conservatives, with 71 percent approval, she is even more unpopular among liberals, with 85 percent viewing her negatively. Overall, slightly more than half of all Americans, 55 percent, view Palin unfavorably.
ABC News Radio's Marco Villarreal in Searchlight, Nev., contributed to this report.