“[Trump] understands that’s what should be done,” Trumka said on Wednesday morning, during an event in Washington, D.C., hosted by the Christian Science Monitor. “We reject the notion that it’s either free trade or protectionism.”

He added, however, that Trump's tariffs should be more targeted, saying he didn't he agree with the decision to levy tariffs on Canada.

The qualified praise of Trump’s controversial trade policies from a labor union federation with deep ties to the Democratic Party is the latest indicator of how Trump is shifting party politics.

Congressional Republicans have by and large rejected Trump’s approach of imposing steep tariffs on allies and adversaries alike, even introducing legislation that would limit some of his trade authority.

But Trumka said that the measures and the retaliatory tariffs imposed by China, Canada, Mexico and the E.U. were ultimately small potatoes.

“The hysteria about ‘there’s a trade war and the sky is falling’ is simply inaccurate and does a disservice to the country,” he said, adding that tough measures against China were particularly welcome.

Republicans in Congress derided Trump’s approach of offering $12 billion in aid to farmers affected by the trade showdown as forcing farmers onto welfare, and called for “trade not aid.” Trumka said that the administration should expand its aid to those affected every sector affected by counter-measures.

Even with farmers suffering, he argued, the country would be better off in the long run if new trade deals resulted.

“Sometimes what’s good for the country may be bad for Joe and Jane in the short term,” Trumka said. “Even the farmers would say we ought to have fair trade agreements,”

In the meantime, Trump entered a very public battle with the conservative Koch network, a major source of Republican funding, amid a push by the Koch-backed Americans for Prosperity against tariffs.

“The globalist Koch Brothers, who have become a total joke in real Republican circles, are against Strong Borders and Powerful Trade,” Trump wrote in a series of Tweets Tuesday .

But despite his support for Trump’s moves to boost trade enforcement and rewrite deals, Trumka remained critical of the president’s other policies.

He said the Trump administration’s actions to defang labor rights and the government agencies that promote them were bad for America's workers. So were moves to undermine the Affordable Care Act and pass tax cuts that have yet to significantly boost wages. Trump’s Supreme Court pick Brett Kavanaugh, he continued, had a history of favoring companies over workers.

“It doesn’t matter, if you’re a worker, and the GDP is 3 percent and unemployment is low if wages are flat, you can’t get healthcare,” Trumka said.

“Unfortunately, the number of things we’ve had to oppose is greater than the number of things we support. And that’s sad,” he added.

Lighthizer, he noted, had still not adopted most of the union requests for the new NAFTA talks, and the possibility of auto tariffs could affect workers negatively.

Still, he declined to rule out a potential endorsement of Trump in 2020.

“We will consider endorsing every candidate,” he said.