As Bernie Sanders' national polling lead grows, Democratic rivals have sought to drive a wedge between him and the people he says his campaign is all about — all in the hopes of peeling off support from members of Nevada's politically powerful unions in Saturday's caucuses. … But for some unions, this isn't a fight they want to have right now.  “I think that we need to listen to what the Democrats candidates are saying about health care, but we can’t lose sight of the fact that the other side wants to tear" apart the Affordable Care Act, said Lee Saunders, president of the American Federation of State, County and Municipal Employees, which is part of the AFL-CIO. “It’s not worth having a major debate about how we get from point A to point B when everyone wants to move along — the other side wants to take us back to before A was in existence."  He said his union, which has 1.4 million members nationwide, isn't planning on endorsing anyone anytime soon.  "We don’t want to be given a false choice of, we’ve got to support single payer or Medicare for All or support incremental changes — all of those things should be put on the table," he told NBC News.  Still, they're encouraging voters to be active participants in the primary — particularly in the delegate process.  "Because there’s a possibility it could be brokered, we want to have a seat at the table," Saunders said, referring to the convention. "This year, we think it's very important that we have members running for delegate status."