I love the irony here but this is 100% meant to bait counter protestors with guns to show up to the next one, especially in Wisconsin, and especially with the current administration that has no problem holding a double-standard (liberal protestors with guns are dangerous, conservative protestors with guns are patriots).
Leftists don't have the same privilege as white conservatives do walking around with an open carry. I hope anyone bringing their firearm to a protest understands the risks involved and is ready/willing to use it if things escalate.