Beatty -- an outspoken critic of the governor -- argued loudly when he was told he and Bening did not have invitations and, therefore, would not be admitted to the event that took place Saturday in an airplane hangar, the Los Angeles Times reported.
The couple and their supporters were blocked at the hangar's entrance by Schwarzenegger aides Darrel Ng and Todd Harris after being told they needed wristbands to get in, the Times said.
"Do we need a wristband to listen to our governor?" Bening asked. "He represents all of us."
As TV cameras and spectators gathered around, Harris told the couple: "If your people had shown a modicum of respect when you came to our events, if you hadn't come with bullhorns and been screaming, I wouldn't really have a problem with it."
Beatty and his "Truth Squad" eventually backed off and listened to the goings-on inside the hangar via loudspeakers.
A grinning Beatty later called the incident "political street theater."
"I think we got our message across by being respectful," he said. "I think it was slightly disrespectful on their part to keep us standing out in the sun."