Jonathan Ernst / Reuters Donald Trump claimed during the campaign that he would be good for union workers.

Candidate Donald Trump pitched himself as the right choice for union workers. He bragged that he’d had good relations with labor unions during his real estate career. He argued that he deserved the AFL-CIO labor federation’s electoral endorsement, which ultimately went to his opponent, Hillary Clinton.

But in less than a year as president, Trump has wiped away several of the modest policy gains that organized labor made during the Obama years. The nominees he’s chosen to fill crucial regulatory roles are already making it more difficult for some workers to join unions and bargain collectively.

These policy reversals have drawn enthusiastic cheers from business lobbies and made a joke of one of Trump’s campaign boasts: “I have great relationships with unions.” Meanwhile, union ranks are hovering near historic lows.

In the last weeks of 2017, the National Labor Relations Board issued a slew of decisions that rolled back worker- and union-friendly reforms from the preceding eight years. The NLRB is the independent federal agency responsible for interpreting collective bargaining law and refereeing disputes between employers, unions and workers.

The new rulings were made possible by Trump’s two nominees to the five-member NLRB ― William Emanuel and Marvin Kaplan ― which flipped the board’s majority from liberal to conservative. The board managed to get several contentious decisions out the door before Dec. 16, when the term of the third Republican member, Philip Miscimarra, expired, deadlocking the board at 2-2.

In one of the most consequential changes, the NLRB reversed a 2011 ruling that helped workers form smaller unions within a single larger workplace. The precedent set during the Obama years allowed, say, nursing home assistants to hold a union election without including all the facility’s dietary aides, maintenance workers and other employees who don’t share similar job duties, wages and gripes with management.

Employers hated that standard, complaining that it led to “micro unions.” By overturning it, the Trump-shaped board made organizing workers at a large facility a far more daunting task. Consider the case they ruled on: After 100 welders unionized at a manufacturing plant, the NLRB found the smaller organizing unit to be illegitimate and said any union election would have to include all 2,500 different types of workers at the company, spanning 120 job classifications.

The board ruled 3-2 along partisan lines in the case. The two dissenting Democratic members said it was “unconscionable” for the Republican majority to make such a sweeping change without at least soliciting briefs from unions and employers. “It is a dereliction of the duty we owe to the parties and the labor-management community,” they wrote.