The question was deceptively simple. At a Wednesday breakfast hosted by the Christian Science Monitor, AFL-CIO President Richard Trumka was asked whether the nation’s largest union might endorse President Trump for a second term.

Trumka, who had been supportive of the president’s overall tariff strategy, did not say “no.” But he told John Gizzi, who works for the conservative publication Newsmax, not to get carried away.

“I don’t want to see in your story: Trumka says he’ll endorse Trump,” Trumka said. “I’m not saying that. I’m saying, we’ll consider every candidate who’s running, and our members will help us decide that.”

A few hours later, Gizzi’s story went up with the headline “AFL-CIO’s Trumka Won’t Rule Out Unions Endorsing Trump in 2020.”

Randi Weingarten, the president of the American Federation of Teachers, went after Trumka on Twitter, before the AFL-CIO condemned the “clickbait” framing of Trumka’s quote.

In reality — and as the story said, below the headline — Trumka mixed some praise for Trump’s trade strategy with criticism of his labor policies. In the 2016 election, Trump had famously outperformed a generation of Republican candidates with union voters and voters from union households.

Since then, he had slipped in the polls with union voters, and Trumka argued that it had happened after he followed more-traditional Republican tactics. While he was “going in the right direction on trade,” Trump had not done enough on wages or health care.

“When he does something that’s right for workers, I tell workers around the country that he’s right,” Trumka said. “When he does something that’s bad for workers, I tell them it’s bad. And unfortunately, the number of things we’ve had to oppose is greater than the number of things we’ve been able to support. Workers are still finding things getting worse for them, not better for them. It doesn’t matter if unemployment’s at 3.9 percent if their wages are low, they don’t have health care and they can’t afford to send their kids to school.”

Why, then, was Trumka unable to clarify the AFL-CIO’s 2020 endorsement? It had a lot to do with the way that the union makes that call. According to its official rules:

AFL-CIO presidential endorsements are determined by a two-thirds vote of the General Board which consists of all members of the Executive Council and the principal officer of each affiliated, national or international union, the principal officer of each trade and industrial department, a representative of each national constituency organization, and allied retiree organization, and young worker organization recognized by the Federation, a representative of each chartered national community affiliate, and regional representatives of the state, area, and local central bodies selected by the Executive Council pursuant to a system promulgated by the Council.

Those rules, since 1976, have led to AFL-CIO endorsements for Democrats. But they do not always come easily. In 2016, the union did not endorse Hillary Clinton for president until mid-June, after she had effectively secured the Democratic nomination.

In 2020, Trump’s political operation would be able to appeal to AFL-CIO affiliates — especially building-trade unions — on the basis of his tariff policies and potentially the renegotiation of current trade agreements. That was less than the promises Trump made as a candidate, which included a massive infrastructure package that was never introduced. But it was more than most Republicans had been able to offer.

“Two-thirds for Trump is inconceivable, but unanimity against Trump might be hard,” said Jeff Hauser, a former communications manager at the AFL-CIO.