Donald Trump, Jr. ripped Ohio Senate candidate Josh Mandel one day before Sen. Ted Cruz (R-TZ) is set to being a four-city tour backing Mandel.

On Friday and Saturday, Cruz is scheduled to stump for Mandel in Dayton, Toledo, Columbus, and Cincinnati. Cruz, like the Club for Growth, stuck with Mandel even after Donald Trump endorsed venture capitalist J.D. Vance.

The Trump family has since been openly feuding with the Club for Growth, which bills its endorsements as “the gold standard” in identifying conservative candidates.

Trump, Jr. went after Mandel on Thursday after journalist David Catanese published quotes about the former Ohio treasurer the forthcoming book This Will Not Pass: Trump, Biden, and the Battle for America’s Future by New York Times journalists Jonathan Martin and Alexander Burns.

“Mandel, acknowledged to Republicans in Washington that he was parroting absurd rhetoric in the primary campaign out of a desire to court Trump and his supporters — but that was simply what he believed it would take to win,” the two reported. “In fact even as he publicly mimicked Trump’s incendiary rhetoric, Mandel would privately reach out to McConnell’s top lieutenants to alert them each time one of his top rivals, J.D. Vance, criticized Washington Republicans — effectively trying to have it both ways with Trump and the GOP leaders he derided.”

Trump, Jr. posted a screengrab of the quotes and said Mandel was “outed as the establishment RINO fraud he truly is.”

Mandel serves [GOP Leader Mitch McConnell] and is owned by the GOP establishment,” he charged. “MAGA can not trust him — Don’t be fooled by this RINO fraud!!!”

Reps. Matt Gaetz (R-FL) and Marjorie Taylor Greene (R-GA) are also backing Vance.