Today, a Seattle City Councilmember is expected to announce legislation that would grant all for-hire drivers in the city the right to collectively bargain with the companies they contract with to provide services, which they currently can’t do under federal law, setting up an entirely new system.

Over the past few years, taxi drivers have affiliated with unions in cities across the country. But since they’re usually independent contractors, they’re not covered by the law that allows them to negotiate directly with taxi companies, like other private-sector employees can. Their only power is to try to influence how cabs are regulated, which determines their pay and working conditions.
But some legal experts think that because Congress explicitly excluded independent contractors from the NLRA, they might have intended to prevent states from letting them join unions as well. “That pre-empts state or local governments from saying 'no no, they do have rights,’” says Jeffrey Hirsch, a professor at the University of North Carolina School of Law. “I do not see this going anywhere.”

O’Brien’s office and the Teamsters disagree, but say they do expect a legal challenge if the measure passes. In a city that elected a socialist and passed one of the county’s first $15 minimum wages, it may have a shot.
Seattle might try something crazy to let Uber drivers unionize - The Washington Post