CLEVELAND — Donald Trump's supporters promised party unity this week at the Republican National Convention. Then his campaign manager called the Ohio Republican Gov. John Kasich "embarrassing" and "petulant" for refusing to show.
The remarks escalated an intra-party feud that had many Republicans groaning and wondering whether the party could conclude this week's festivities with any semblance of civility.
"John Kasich is being petulant," said Paul Manafort, Trump's campaign manager, to reporters Monday morning at a Bloomberg breakfast.
Kasich — the last member of the crowded GOP primary to end his campaign and whose exit from the race cleared the path for Trump's nomination — doesn't appear to be taking the bait.
In remarks to an Illinois delegation Monday afternoon, Kasich did not utter the presumptive nominee's name once. But in an interview to be broadcast on NBC Nightly News, Kasich said Trump would "have to change everything that he says" before he would endorse the celebrity businessman.
"I don't hold any personal animus toward Donald Trump," Kasich said in the interview. "We are just two companies that have different values, different directions and different philosophies."
In a phone interview with Fox News Channel in the midst of the GOP convention Monday night, Trump said Kasich should have attended "from the standpoint of honor."
Other Ohio Republicans swung behind Kasich.
"Manafort still has a lot to learn about Ohio politics," Ohio GOP Chairman Matt Borges wrote on Twitter. "Doesn't know what he's talking about. Hope he can do better."
In his public dispute with Kasich, Manafort also had drawn in Ohio Republican Sen. Rob Portman, saying Portman was "very upset" with Kasich and believes the governor's lack of support for Trump is hurting his own re-election campaign.
Portman is locked in one of the year's toughest Senate races. While he has endorsed Trump, he is hardly an enthusiastic backer. Portman has said he plans to be on the convention floor occasionally this week, but is not delivering a speech.
Portman's campaign quickly disputed the idea of a rift between the Ohio senator and governor, who are longtime friends and colleagues.
"That's totally false," said Corry Bliss, Portman's campaign manager. He added that Portman and Kasich are "working hand in hand" on the senator's campaign and "any suggestion otherwise is inaccurate."
While Kasich won't be stepping inside the convention center, he has an active schedule in Cleveland, planning to meet with delegates from several states and speak to the U.S. Hispanic Chamber of Commerce. He also addressed the NAACP convention on Sunday, an invitation Trump declined.
Kasich's advisers say he doesn't plan to speak out aggressively against Trump during the convention week because he doesn't want to be "rude." John Weaver, Kasich's chief strategist, says the Ohio governor will turn his focus this fall to campaigning for down ballot races. Recent polling put Kasich's approval rating well over 50 percent in Ohio.
"It's going to be a pretty tremendous headwind in the effort to keep control of the Congress, so he's going to take a leading role in that," Weaver said.
Ohio is one of the biggest prizes in the presidential election and almost certainly a must-win for Trump. Ohio, worth 18 electoral votes, has been carried by every winning candidate for president since 1964, and by a margin of less than 3 percentage points in the past four White House elections.
AP writers Daniel Sewell in Cincinnati, Julie Carr Smyth in Columbus, Ohio, and Kathleen Ronayne in Claremont, New Hampshire, contributed to this report.