“We’re going to work hard for him to carry the state. But if he or his campaign keeps criticizing John Kasich, he’s going to lose. So that’s something that needs to stop,” Ohio Republican Party Chairman Matt Borges told RCP. “We’re the people who have been doing nothing but winning elections in this state for 25 years. He knows he needs to listen to people who know what they’re doing.”

The feud could create trouble for the Trump campaign’s hiring in Ohio. The Cincinnati Enquirer reported that one veteran Republican and close Kasich ally turned down an opportunity to join the campaign.

“Do endorsements matter? Not really. But does Donald Trump have a message right now that can win Ohio? No,” said Chris Schrimpf, Kasich’s communications director.

“The most important thing to Governor Kasich right now is making sure Rob Portman gets re-elected,” Schrimpf said, referring to the Republican senator engaged in one of the most competitive re-election contests this cycle. “It’s the rare instance where the Trump folks would be lucky that the Portman campaign is one of the best run in the country with one of the best ground games in the country, which they’ve set up on their own.”