Audience groans as Trump's campaign chair slams John Kasich in his home state

Audible groans could be heard Monday morning when Donald Trump's campaign chair, Paul Manafort, ripped Ohio Gov. John Kasich in his own state.

Speaking ahead of the Republican National Convention in Cleveland, set to officially open Monday, Manafort was asked by an MSNBC host why the Republican governor wasn't attending the event taking place in his own backyard.

"You know what? He's making a big mistake. He's making a big mistake," Manafort said. "[H]e's hurting his state. He's embarrassing his state, frankly."

The comment prompted the crowd to voice its disappointment by way of audible groans and murmurs.

Ohio GOP chairman Matt Borges rebuked Manafort shortly thereafter.

"Manafort still has a lot to learn about Ohio politics," Borges wrote on Twitter. "Doesn't know what he's talking about. Hope he can do better."

"Ohio loves our governor," he added. "He turned this state around and united Ohioans."

Kasich, who challenged Trump for the GOP nomination, remains popular in Ohio, enjoying an approval rating above 60%.