Bernie Sanders (I-VT) and some Democratic senators did not hold back their criticism of outgoing colleagues, Sens. Joe Manchin (I-WV) and Kyrsten Sinema (I-AZ) for voting down one of President Joe Biden’s nominees. On Wednesday, Manchin and Sinema voted against the nomination of Lauren McFerren to another term on the National Labor Relations Board. The nomination failed by one vote. The NLRB oversees U.S. labor laws and makes important decisions about labor disputes, collective bargaining, and unfair labor practices. Its five members serve five-year terms.

There are two types of “independents” who presently caucus with Senate Democrats: those who are basically Democrats, in all but name, and those who are barely not Republicans. On Wednesday, Sens. Joe Manchin, I-W.V., and Kyrsten Sinema, I-Ariz., offered a clear reminder of which category they fall into, serving as the two “no” votes that killed the possibility of a pro-union majority helming the National Labor Relations Board through 2026. Lauren McFerran is one of three Democrats who currently serves on the five-member NLRB, which under President Joe Biden has...