She was asked to surrender her weapon or leave. She chose the former, but still had a Pa. State Trooper shadow her until the event was over.
I believe Mezzacappa is open carrying because the Sheriff has revoked her license to carry concealed.
While she certainly has the right to prance around with her gun in a holster, she does not have the right to transport her gun in a car. That requires a license.
Under Pennsylvania's Uniform Firearms Act, a "firearm" is defined as follows:
"Any pistol or revolver with a barrel length less than 15 inches, any shotgun with a barrel length less than 18 inches or any rifle with a barrel length less than 16 inches, or any pistol, revolver, rifle or shotgun with an overall length of less than 26 inches. The barrel length of a firearm shall be determined by measuring from the muzzle of the barrel to the face of the closed action, bolt or cylinder, whichever is applicable."A license is required for "carrying a firearm concealed on or about one's person or in a vehicle throughout this Commonwealth." There are exceptions for hunting and going to the range, but not for political fundraisers.