House Majority Leader Kevin McCarthy said Monday that some Republicans are starting to panic as Donald Trump’s primary win in South Carolina increases the probability that the billionaire will emerge as the GOP nominee.

“I think there’s more than a 50 percent chance he’s the nominee,” McCarthy said in an interview on MSNBC’s Morning Joe show. “And I think that’s what’s setting in for a lot of people. Could they get their heads around Trump being the nominee?”

The California Republican said the contest for the GOP nomination is now effectively a tw0-person race between Trump and Florida Sen. Marco Rubio.

McCarthy did not say whom he would support for president, but when asked whether Ohio Gov. John Kasich would be effective, he responded, “I think John Kasich would be an excellent president. I think he would be — on paper, he seems like the very best.”

He explained that governors in general have better training to become president, saying, “They can’t print more money, they have to balance the budget. They pick a Cabinet, they run agencies they didn’t create and try to make them effective.”