Newsom takes selfie with scores of attendees at @CalNurses convention pic.twitter.com/pCVout6WWg&mdash; Melanie Mason (@melmason) September 22, 2017 Lt. Gov. Gavin Newsom has made his most explicit endorsement yet of a controversial single-payer healthcare proposal that has roiled Democratic politics in California.Newsom appeared Friday before the California Nurses Assn., the most ardent backers of SB 562, a stalled bill to establish a system in which the state would cover all residents' healthcare costs.&nbsp;"There&rsquo;s no reason to wait around on universal healthcare and single-payer in California," Newsom said. "It's time to move 562. It's time to get it out of committee." The line prompted cheers and a standing ovation from the audience of about 1,500 members of the nurses' union.He capped off his remarks with a promise: "If we can&rsquo;t get it done next year, you have my firm and absolute commitment as your next governor that I will lead the effort to get it done. We will have universal healthcare in the state of California."Enthusiastic nurses&nbsp;in the room heard an unequivocal backing of their effort to push forward with the bill."When he says he's going to get this done, he means, seriously, that he will pass SB 562 and make sure that there is healthcare for all Californians," said&nbsp;Catherine Kennedy, a neonatal nurse from Roseville.But speaking to reporters after his address, Newsom&nbsp;was less clear in embracing the specifics of the proposal."I 100% support moving this process along, getting this debate going again and addressing the concerns, the open-ended issues that the nurses themselves have acknowledged as it relates to the need of going through the legislative process and to fill in the blanks on the financing plan, among other issues," he said.