SAN FRANCISCO, CA - FEBRUARY 26: San Francisco Mayor Mark Farrell speaks to union members during a rally outside of San Francisco City Hall on February 26, 2018 in San Francisco, California. Hundreds of union members held a rally outside of San Francisco City Hall as the US Supreme Court begins to hear oral arguments in the Janus V. AFSCME case that union memebers and supporters claim would limit their right to union representation by allowing members to not pay dues but still receive representation. (Photo by Justin Sullivan/Getty Images)