U.S. Rep. Paul Gosar acknowledged Monday that "it does sting" that six of his nine siblings appeared in an ad for his political opponent and blamed the attacks on former President Barack Obama.

Speaking on "The Mike Broomhead Show" on Phoenix radio station KFYI-AM (550), the four-term Republican fired back at his brothers and sisters for taping ads for his Democratic rival David Brill that put an unwanted national glare on Gosar and a family rupture.

"It always hurts, Mike. You know, blood is supposed to be thicker than water," Gosar told Broomhead. "But, you know, this actually details exactly what the left, what Barack Obama actually asked progressives to do, is to get into family and friends, in their face, and not let up."

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Gosar represents western Arizona's 4th Congressional District, the state's most Republican-leaning district, where the GOP has a lopsided voter-registration advantage over Democrats. But the unusual step of his family members urging voters to vote against their brother has made Gosar's race against Brill a national story, at least for now.

Gosar ascribed Brill's and his siblings' strategy to Saul Alinsky's 1971 book, "Rules for Radicals," a guide to organizing a movement that has been used by people on the political left and right.

"You know, using Alinsky’s 'Rules,' trying to marginalize somebody in regards to trying to call them bad names and 'you’re sick' and this other kind of crap," Gosar said. "But you know the thing about it is, I have worked my district and my district knows me. I’m a very coherent and very accomplished member of Congress, so I don’t have to explain myself to six radicals."

Dave Gosar shrugged off his brother’s comments Monday.

"He’s capable of saying anything. It’s par for the course,” Dave Gosar said.

"He’s so extreme that his take on this is that we’re so extreme. Here’s a guy who wants to block transgender people from using the bathroom of their gender identification. Here’s a guy who wants to kick DACA kids out of the country, who’s marching with white nationalists in Britain.”

“It surprises me how big this has gotten, how messy this has gotten,” Dave Gosar said.

Brill unveiled ads last week with Gosar's siblings in which they say he needs an intervention.

"It would be difficult to see my brother as anything but a racist," sister Grace Gosar says in an ad for Brill.

"I think my brother has traded a lot of the values we had at our kitchen table," sister Joan Gosar says in another.

"It's just sad that this is how they look at this, but it also shows you, Mike, that how the tenor has changed in this country, almost to the brink of like a civil war," Gosar said Monday. "We’re intolerant of other people’s ideas. I forgot I was born into a family of geniuses, that the last people to know the last of the Darwinians are them."

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Unlike most of their children, Gosar's parents are conservative and agree with his politics.

"I share the same philosophy and policies that Paul does," Bernadette Gosar told the New York Times. "He’s done a hell of a job for Arizona, and they love him."

Paul Gosar acknowledged the family rift pains him.

"It does sting," Gosar said. "My kids have taken it very negatively. My son is named after my brother and he was confronted by a number of different people saying, 'Listen, so you’re the Gaston Gosar who took your dad’s name and tried to destroy it?' And he goes, 'No. Unfortunately, that’s my uncle, but his name is Francis Gaston.' I think what doesn’t kill us makes us stronger."

In his fourth term, Gosar has made a national name for himself with controversial statements and passing along outlandish conspiracies.

Gosar's siblings, all of whom grew up with him in western Wyoming and live outside Arizona, first went public with their differences with their brother last year after he suggested that liberal donor George Soros may have been a Nazi collaborator as a youth in an interview with "Vice News" for HBO.

For a year, many of his siblings have peppered him with insults on social media. In interviews with The Arizona Republic, several of his siblings acknowledged they were no longer close to their brother because of the intensity of their disagreement with his political positions.

Gosar has offered no shortage of controversies throughout the year.

Before Trump's State of the Union speech this year, Gosar called for the deportation of undocumented immigrants who were attending the speech at the invitation of Democratic members, including from Arizona.

This summer, Gosar drew national ridicule for suggesting during a congressional hearing that his training as a dentist made him an expert on body language.

"By the way, I’m a dentist, OK? So I read body language very, very well. And I watched you comment in actions with (U.S. Rep. Trey) Gowdy (R-S.C.). You got very angry in regards to the Gold Star father,” Gosar said. "That shows me that it’s innately a part of you and a bias."

After that, he delivered a cringeworthy lecture on the government that seemed to fizzle midthought.

"We are not a democracy. We are a constitutional republic,” he said. "That is why we have, um, two ways, both from a democracy, voting, and then from, the, uh, where we have the, uh, Electoral College. So make sure that we get that straight."

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