Rep. Darrell Issa (R-CA) made it clear this morning that when he calls a committee hearing he’s not going to tolerate any questions from Democrats — or answers from witnesses — that undermine him.

During a House Oversight and Government Affairs Committee hearing looking into whether an ATF program to interdict gun smuggling along the U.S.-Mexico border went horribly awry, Democratic committee members tried to ask ATF witnesses whether the nation’s gun laws are too weak and make prosecutions difficult. Issa would have none of it, calling any such testimony invalid.

“I want to caution the witnesses that the scope of this, your testimony here is limited, and that it’s not about proposed legislation and the like and under House rules would not fall within the scope of this,” Issa said. “So, anecdotally you can have opinions but ultimately it would not be considered valid testimony.”

Watch Issa’s heavy-handed effort to control the hearing here.