There’s no doubt about that. See this (emphasis mine):
Mr. Freeman pointed to a case involving a unionization effort at Yale-New Haven Hospital, where an independent arbitrator ruled in 2007 that the hospital had violated an agreement calling for both sides to respect principles aimed at guaranteeing a fair election. The arbitrator wrote that the workers “ were threatened with more onerous working conditions and even loss of their jobs if the union were selected.”
She said the workers were victimized and ordered the hospital to pay the 1,700 workers a total $2.2 million - the amount the hospital had paid to antiunion consultants. She also ordered the hospital to repay the union its $2.3 million in organizing expenses. Professor Freeman noted that this $4.5 million penalty, which was ordered outside the National Labor Relations Act, was 20 percent more than the $3.6 million that the labor board awards on average each year to all workers nationwide for all back pay for being retaliated against for supporting a union. He cited a paper by Morris M. Kleiner and David Weil stating that “the Act for decades has been ineffective in curbing behaviors that are antithetical to its fundamental aims.”
And this is interesting, too:
He noted that there was a 20 to 30 percent gap between the percentage of workers who said they wanted union representation and those who had unions - the largest gap among advanced English-speaking countries.