Donald Trump. AP Photo/Mary Altaffer Conservative radio host Hugh Hewitt on Wednesday said the GOP should look to change the rules at this summer's Cleveland convention so it can ditch Donald Trump as its nominee.

The host came to that conclusion after what he called the worst 72 hours for the party in more than 15 years.

"The worst 72 hours for the Republican Party since 2000 when the George W. Bush DUI was dropped," he said on his program, adding, "We're going to get killed. We're going to get killed."

Hewitt said that what the "self-savaging" party leaders inflicted on Trump after he continued to pursue a racial line of attack against a federal judge was like nothing he had ever seen.

The latest Trump firestorm centered around his persistent attacks on US District Judge Gonzalo Curiel over his Mexican heritage. The Manhattan billionaire said Curiel cannot fairly preside over a civil case involving his now-defunct for-profit real estate school, Trump University, because he is of Mexican descent and Trump is "building a wall" along the US/Mexico border if elected in the fall.

Curiel is from Indiana.

Republicans from all sides of the party have publicly condemned the remarks and demanded that Trump change his tone. In a Tuesday late-afternoon statement, Trump took a step back from the attacks but did not apologize. He made no mention of his attacks against the judge in his prepared post-primary speech later that night.

"Paul Ryan had to come out and say those are racist comments," Hewitt said. "Sen. Mark Kirk unendorsed him. Sen. Jeff Flake of Arizona said, 'Well, he might not be our nominee.' Mitch McConnell hammered him. It was a day of self-savaging of the Republican nominee, I've never seen anything like it. And by the end of the day, it was clear: Trump's campaign was in free-fall and on fire."

Listen to some of the audio below:

He said that Tuesday was the day when it occurred to him that Trump had no chance of winning in November.

Acknowledging that Republicans have "never" defeated Bill and Hillary Clinton, Hewitt said: "We're not going to beat her now with Donald Trump.

"Right now the Republican Party is facing — the plane is headed towards the mountain after the last 72 hours," he said.

Donald Trump. AP Photo/Jae C. Hong Hewitt said the Republican Party "ought to get together and let the convention decide."

He called for a rules change that would inhibit Trump from becoming the party's nominee in Cleveland.

"And if Donald Trump pulls over a makeover in the next four to five weeks, great, they can keep him," he said. "It would be better if he had done so five weeks ago."

Hewitt is not the first to suggest Republicans change the convention rules to stop Trump.

On Tuesday, the former New Jersey chairman for Ted Cruz’s 2016 White House bid said delegates have a “moral obligation” to launch an “insurrection” and “unbind” themselves to halt the billionaire’s rise. Moreover, a Wall Street Journal editorial on Wednesday suggested that if Trump “doesn’t start to act like a political leader” he could “hear rumblings that delegates are looking for someone else to nominate.”