Randy Bryce, the Democratic candidate seeking to replace Paul Ryan in the House, now finds himself the target of criticism from his own brother.

The progressive candidate, dubbed “Iron Stache,” achieved viral fame and a massive fundraising haul upon first announcing his bid against House Speaker Ryan (R-WI). And now he’s the target of an intrafamily political attack.

In an ad released Tuesday by the Congressional Leadership Fund, a PAC closely aligned with Ryan, Bryce's brother James, a police officer, discusses why he will vote for Bryan Steil, the Republican candidate in Wisconsin’s 1st congressional district.

“When people refer to police officers as terrorists, that hits a little close to home,” James says in the ad, referring to a tweet from Bryce from 2012 lamenting police tactics in Wisconsin.

“Randy is the proud son of a police officer and has a deep respect for law enforcement officers, including his brother, even when they have political disagreements,” Bryce spokesperson Julia Savel said in response to the ad.

But the familial tiff grew even more complicated on Wednesday as the Bryce boys’ mother Nancy wrote a letter demanding the ad be taken off the air.

“I’m used to my sons getting into disagreements with each other—every mom is. And I understand that my boys see the world differently when it comes to politics,” she wrote, in the letter obtained by the Milwaukee Journal-Sentinel, without directly criticizing her son James for participating in the attack ad.

“There is now a group of people from Washington who consider it a good idea to pit my boys against each other for their own political gain. But they didn’t consider a mother’s pain at seeing her children used as tools in a political fight, splashed with millions of dollars of ads across the airwaves.”

She continued: “I am disappointed and, frankly, disgusted that we are at a point where the Republican party is so focused on sowing division in our families and communities, with such little regard for the truth.”

Asking Steil to remove the ad, she concluded: “Shame on this ‘super PAC’ for running these ads, shame on its leader Paul Ryan for funding them, and shame on people of good conscience who choose to sit idly by and watch this pain inflicted upon a family in the name of partisan politics.”

Bryce became a national sensation with the release of a biographical ad in 2017 showing his experience as an ironworker and both his and his mother’s health-care struggles. He has raised more than $6 million and has over $1.6 million on-hand, while a recent New York Times poll found him trailing Steil by six points.