Under the existing regulations, workers typically vote within 45-60 days after a union gathers enough signatures from workers saying they want to hold an election. The new rules could cut that time by days or even weeks by simplifying procedures and putting off some challenges until after the election is held, reducing legal delays.
Unions call the changes a modest fix to prevent companies from using stalling tactics to delay a vote while workers can be subject to harassment and even illegal firing. Republicans argue the new rules will lead to "ambush" elections that barely leave managers enough time to respond or counsel against forming a union.
The NLRB has been the focus of intense partisan bickering since President Obama gave the independent agency its first Democratic majority in nearly a decade. The board has issued a number of rules and decisions that tend to favor unions over business.
"The National Labor Relations Board seems to be hell bent on changing processes across the board more for political reasons than for substantive reasons," Sen. Lindsey Graham (R., S.C.) said during floor debate.
But Democrats said the rules address some of the most abusive situations where companies manipulate procedures to conduct antiunion campaigns.
"All the board has done is to send a clear message to employers: You can't abuse the process to buy yourself more time to intimidate workers," said Iowa Sen. Tom Harkin, Democratic chairman of the Senate Health, Education, Labor and Pensions Committee.
The new rules could help unions expand in the private sector, where membership has dwindled to about 6.9 percent of all workers. Retailers like Target and Wal-Mart are concerned that the new rules will encourage unions to step up organizing at their stores.
"With only about 5 percent average unionization, retailers are low-hanging fruit for union organizers," said David French, a vice president of government relations for the National Retail Federation.