In a major victory for the IBEW and unions, the Senate rejected the Tribal Labor Sovereignty Act on April 16, avoiding what would have been the biggest rollback in workers' rights since the anti-union Taft-Hartley Act of 1947.

The bill would have exempted any business or corporation partially or wholly owned by a Native American tribe from the National Labor Relations Act, which guarantees workers the right to join a union. It would have applied to all employees of those businesses, including non-tribal citizens. More than 600,000 workers would have lost protections guaranteed by the NLRA if the bill had passed, according to the AFL-CIO.

The House passed the bill in January, but it needed 60 votes in the Senate, where it fell five votes short of breaking a filibuster. It is unclear if the Senate will take it up again. President Trump had not voiced an opinion, but he was expected to sign the bill if it reached his desk. Among its supporters was the U.S. Chamber of Commerce.

"This was a great win for the IBEW and all of labor," said Austin Keyser, director of the Political and Legislative Affairs Department. "We fully support Native American tribes having sovereign power over their own governmental issues, but this bill had nothing to do with that. Instead, it was an attempt by rich and powerful interests to strip hundreds of thousands of Americans of their fundamental rights at work."

Indeed, some tribal leaders made little attempt to disguise their intentions of eliminating union representation.

"I would liken it to what happened with the air traffic controllers strike a number of years ago," a representative for the Chickasaw Nation told a congressional hearing earlier this year. "We obviously are not on as large a scale, but that is the type of activity that would interfere with what we are doing."

The IBEW saw that first hand. Diamond Bar, Calif., Local 47 represents about 30 slot-machine technicians at a casino in Cabazon owned by the Morongo Band of Mission Indians. The local union voted to ratify an agreement following contract negotiations, but negotiators for the tribe refused to recommend tribal members approve it because they had been emboldened by Congress' potential action.

Keyser thanked members for contacting their representatives to oppose the bill, noting that attendees during the annual political conference made it a point of emphasis while lobbying on Capitol Hill.

"IBEW members understood this bill would have emboldened our opponents if they had been successful," he said. "We certainly would have been targeted at some point. I'm really pleased with how we worked with our friends and allies to defeat this terrible piece of legislation."

It wasn't easy. Eight Senate Democrats, the majority of whom are up for re-election this year in states with large Native American populations, voted in favor of the bill. Ohio's Rob Portman was the lone Republican to vote against it.

"I want to thank our members and supporters who contacted their representatives urging them to vote no," International President Lonnie R. Stephenson said. "I'm convinced they made a difference, but we must remain vigilant. If we've learned anything, it's that more attacks are coming from this Congress."