Minutes later, as Ms. Greene started to play a video of former President Barack Obama discussing the national debt, police forcibly removed and used a stun gun on a second man, identified later as Johnny Keith Williams of Dallas, Ga., who had stood up and started to heckle.

The altercations dominated the town hall, which also attracted dozens of demonstrators outside the event for hours, waving signs and protesting Greene’s MAGA stances. Greene, meanwhile, thanked the roughly 30 law enforcement officers for the aggressive approach.