It’s one of the most brutal political ads of the season, if not the century.

At first glance, the video released Friday by Dr. David Brill doesn’t seem out of the ordinary. A series of his supporters are shown on the screen talking about his opponent, Rep. Paul Gosar, isn’t working for his Arizona constituents.

“He’s not listening to you and he doesn’t have your interests at heart,” one man says.

Pretty ho-hum stuff—until the last few seconds of the spot, when each of the six Brill supporters reveals, one by one, that their last name is Gosar, too.

“Paul Gosar’s my brother,” one of the siblings says.

“And I support Dr. Brill,” another says.

The Phoenix New Times, which first reported the ad, said it is one of several featuring some of the right-wing congressman’s estranged brothers and sisters speaking against him in harsh terms.

"It would be difficult to see my brother as anything but a racist,” Grace Gosar says in one.

Her brother, David Gosar, told the newspaper they didn’t want to publicly oppose him but felt they had no choice given his hard-core views on immigrants.

Earlier this year, Gosar — a fourth-term congressman in a staunchly Republican district — suggested that Capitol Police arrest any “illegal aliens” who might be attending President Trump’s State of the Union address.

The Gosar campaign had no immediate public reaction to the Brill ads, which are only the latest instance of prominent Trump backers facing criticism from family members: