It wasn't the first time Biden took aim at Romney's remark. On Friday the vice president also pulled the binder while criticizing Romney.

The inclusion of a binder is an escalation of Biden's rhetoric on attacking Romney over the story. Even before he started waving around the binder, Biden has made a point to attack Romney over the remark.

"And you heard [in] the debate last night when Gov. Romney was asked a direct question about equal pay [and] he started talking about binders," Biden said at another speech on Wednesday, the day after the second presidential debate. "Folks, the idea that he needed to ask where a qualified woman was — he just should've come to my house. He didn't need a binder."