WASHINGTON (Reuters) - Former Massachusetts Governor Bill Weld, the first Republican to challenge President Donald Trump for their party’s presidential nomination in 2020, said on Sunday that six more years of Trump’s “antics” in the White House would be bad for America.

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Weld said the national emergency that Trump declared on Friday to obtain funding for a wall at the U.S.-Mexico border showed his readiness to divide the country.

“I don’t think he knows how to act. He thinks he has to humiliate whoever he’s dealing with or else he’s half a man,” Weld told ABC’s “This Week” in an interview.

“The emergency declaration is just one example of that. Congress thought they had a deal. He says: ‘Oh, you think you have a deal? I’m going to show you a deal. I’m going to show you who’s boss,’” he added.

Weld, 73, said on Friday he was pursuing a Republican primary challenge against Trump in 2020.

It would be a long-shot bid as opinion polls show Trump’s re-election is overwhelmingly supported by Republican voters, but Weld defended his own candidacy.

“It is part of my thinking to make sure he doesn’t repeat, we don’t have six more years of the antics,” Weld said. “That would be bad for the country.”

Other Republicans have flirted with the idea of challenging Trump, including former Ohio Governor John Kasich and former Senator Jeff Flake of Arizona.

Weld ran as the Libertarian Party’s vice presidential candidate in 2016 and returned to the Republican Party this year.

He now intends to take aim at Trump policies that have pushed the U.S. budget deficits to nearly $1 trillion a year.

“The president is reckless in spending. They’re spending $1 trillion a year. They don’t have that. It’s going to crush Generation Xers and millennials,” he said.

Weld also dismissed his own Republican critics who have accused him of switching allegiances and who say they want Trump to run without a primary challenger in 2020. “I think it’s not what the country needs, to put it mildly,” he said.