WSJ:

A fight among labor unions over who would control a proposed $50 million super PAC has slowed the creation of a unified effort to boost the chances of labor-friendly Democrats winning the White House and control of Congress in the November election.

A senior political strategist for unions first laid out the plan in February before dozens of union presidents and other labor leaders at the winter meeting in San Diego of the executive council of the AFL-CIO, the nation’s largest union federation.

But the efforts have been delayed since then, in part over disputes about who would receive credit for the work done, according to people familiar with the talks.