Two years ago the high court was on the verge of reversing a 40-year-old ruling, saying non-members must pay fees to public employee unions because they profit from wages and benefits obtained by the union.
But when conservative justice Antonin Scalia died that case ended in a 4-4 stalemate. Now a virtually identical case is being heard with President Donald Trump appointee Justice Neil Gorsuch on the bench. He is expected to break the tie and rule against the unions.
A Sacramento rally tried to reaffirm public workers unions' commitment to fight for worker rights even if they lose the case in court.