President Donald Trump’s performance in the White House will make it harder for Republicans — and billionaires — in the coming elections, two of his most prominent critics said Saturday.

Billionaire businessman Mark Cuban and former Florida Gov. Jeb Bush lashed out at the Republican president during separate remarks at a summer festival in New York City’s Central Park.

Cuban, who owns the Dallas Mavericks basketball team, said he may challenge Trump in 2020.

“If he lasts four years, I’ll be there to kick his (butt),” Cuban declared as the young New York crowd roared. “We’ll see. I’m not making any proclamations yet.”

Cuban also warned that Trump “might ruin the path” for another billionaire outsider to run for president in the future.

“He’s not setting the best example,” Cuban said.

After six months in office, Trump and his party have failed to enact any major legislation. His poll numbers are near historic lows and an investigation into Russian interference in the last election is focusing on his closest aides and family members.

Energized Democrats hope they can capitalize on the GOP’s political struggles in next year’s midterm elections when the House majority is at stake.

Bush, a regular target of Trump’s personal attacks during the 2016 Republican primary election, said he would not run for president again. He also tried to distance his party from the new president, noting that Trump was registered as a Democrat in recent years.

“He’s not really affiliated with the party, just to be clear. He’s Trump,” Bush said, speaking less than a mile from Trump Tower.

Bush also lamented the rise of celebrity politicians — Cuban, among them — as he pondered the future of the GOP.

“We may have really talented people that are really good on TV being our leaders for a while until we sort things out,” Bush said, noting that Cuban was on Saturday’s speaking program. “Ideas and policy really matter. It’s not just about personality.”

He said Republicans have “a huge opportunity” with control of the White House and both chambers in Congress. Should the GOP squander that, he said, Republicans may struggle in 2018 and 2020.

Despite the criticism, Bush said he’s rooting for Trump to succeed.

“I find him deeply troubling in a lot of ways. But I pray for him every night. And I pray for our country every night,” Bush said. “I care about my grandkids.”

(AP)