"Paul Gosar, the congressman, isn't doing anything to help rural America," says Grace, identified on screen in a new 60-second political ad as a rural physician.

"Paul's absolutely not working for his district," says David, a lawyer.

"If he actually cared about people in rural Arizona, I bet he'd be fighting for Social Security, for better access to health care," says Jennifer, a medical interpreter.

"He's not listening to you, and he doesn't have your interests at heart," says Tim, a private investigator.

The clips of passionate Arizonians slamming Congressman Paul Gosar seem like pretty standard attack-ad fare—until the 0:42 mark when Tim says "My name is Tim Gosar," followed by the other speakers revealing their full names: David Gosar, Grace Gosar and Jennifer Gosar. Just in case the point is lost on viewers, Grace says "Paul Gosar's my brother," and two other siblings—Joan and Gaston—also show up to formally endorse their brother's political opponent, Dr. David Brill. The ad was released Friday on social channels by the Brill for Congress campaign.

Gosar, who represents Arizona's 4th congressional district, is a fringe figure. Last October, he gave an interview to Vice News in which he claimed the white nationalist rally in Charlottesville that August may have been a false-flag operation organized by an "Obama sympathizer" and paid for by billionaire investor and political activist George Soros, parroting Alex "Infowars" Jones. Gosar also told Vice that 88-year-old Soros, who survived German-occupied Hungary, had "turned in his own people to the Nazis"—a common slander against Soros by conspiracy theorists.

The Daily Miner of Kingman, Arizona, thereafter published an open letter from Joan, David, Tim, Grace, Gaston, Jennifer and Pete Gosar (Pete doesn't appear in the ad above) distancing themselves from their brother. (In total, Paul Gosar has nine siblings.) It began,

We watched the interview of Paul Gosar on Vice News and believe Paul owes George Soros a personal apology. This is a matter of right and wrong, not politics.

The Brill campaign's new ad has become the talk of Twitter. Last night, Astead W. Herndon, a national politics reporter at The New York Times, tweeted a link to it and said that it was "My kind of petty":

A few hours later, Herndon offered a multi-part update:

Bill Kristol, co-founder of the conservative journal The Weekly Standard, is among those taking to Twitter to applaud the Gosar siblings for doing the ad:

Kristol also shared a link to a wrenching companion video titled "A family defends its honor," also released by the Brill for Congress team, in which the Gosar siblings discuss the pain of participating in the campaign against their brother. "None of this is pleasant for any of us," says David Gosar. "It's horrible to have to do this," says Jennifer Gosar. "To speak out against my brother, it brings sadness to me," says Joan Gosar.