Tobin was a lukewarm supporter of the National Labor Relations Act (NLRA). He did not oppose its passage, but expressed deep concern that the Act did not expressly protect craft unionism and allow the creation of craft-based bargaining units. Tobin convinced the AFL to seek introduction of an amendment permitting bargaining units along craft lines. But although Senator Robert F. Wagner agreed to submit the amendment, he failed to do so. After the quick growth of the CIO under the NLRB, Tobin became disenchanted and suggested that the NLRA be repealed and the NLRB disbanded. In time, Tobin came to strongly support the Act.