The incident happened on South Tryon Street in the Steele Creek neighborhood of Charlotte, North Carolina.
Several others people said that this wasn't the first time something like this happened.
At least four different parties described the experience at the early voting location that nearly escalated to violence.
The volunteer said he approached a group of people he believed were taking pictures of some of the Republican volunteers, and several members of that group cursed at him, yelled out racial slurs and a man flashed a gun.
Police said a man was arrested Wednesday evening. Officers said he was carrying a BB gun in a holster, which was seized as evidence.
Police said they are in communication with the FBI to determine whether federal charges will be added.
Two others who were with the suspect have not been charged after the officers determined they did not violate any laws.