And why did no one man the fuck up and beat the snot out of him and his friends? This isn't a pearl-clutching, "call the violent authorities" issue. This is a "beat the fuck out of them on sight" issue.
This and anyone trying to subvert the election process, especially by intimidating voters, have no life value, and should not exist. Arresting them should be the best thing that happens to these terrorists.
Brandishing a weapon to intimidate could maybe be argued as a threat, and perhaps a self defense of, "I felt threatened", may carry weight, especially when the weapon is illegal brandished. Probably not, but the dude should have had his ass kicked before getting arrested, imo.
If there isn't a clear case of self defense, it might be illegal. Classic internet tough guy speak from the OP. No sense in escalating or getting tied up in it. Just call the cops and leave it to them.