Their complaints reflect a broad sense of disappointment among many labor leaders, who say the Affordable Care Act has subjected union health plans to new taxes and mandates while not allowing them to share in the subsidies that have gone to private insurance companies competing on the newly created exchanges.

After dozens of frustrating meetings with White House officials over the past year, including one with Obama, a number of angry labor officials say their members are far less likely to campaign and turn out for Democratic candidates in the midterm elections.

“We want to hold the president to his word: If you like your health-care coverage, you can keep it, and that just hasn’t been the case,” said Donald “D.” Taylor, president of Unite Here, the union that represents about 400,000 hotel and restaurant workers and provided a crucial boost to Obama by endorsing him just after his rival Hillary Rodham Clinton had won the New Hampshire primary.