My late father who was shop steward in the UE, always said that the AFL-CIO merger was the single worst thing the Communist Party ever did in the U.S. The CIO, the best of the labor movement, merged with the worst of the labor movement on the worst's terms. Most of the time the merger ended up with the CIO union dissolved, and the contract turned over to the AFL rival. Even where that did not happen, in practice the leadership, and rules for how the union was run were AFL. The "merger" consisted of the CIO dissolving itself, and turning members over to the AFL. A few CIO unions escaped this, and the rump end of a few others (such as the remnant of the UE - though not in the shop where my father worked), but CIO suicide was mostly what it was. And you could thank that for Taft-Hartley too. The AFL-CIO threatened to take to the streets if it passed. And Congress laughed - knowing that by "take to the street" they meant a protest march, and some hot air. If the CIO had still existed, that threat would have been scarier. Horrid as Truman was, he did veto Taft-Hartley. You would only have had to shift a small number of legislators to have upheld that veto; so odds are the continued existence of the CIO would have made the difference.