Can billionaire tax cure California’s health-care woes?

California’s $200 billion-a-year Medicaid program, known as Medi-Cal, is one of the largest public healthcare systems in the nation. Behind the staggering price tag lies a program repeatedly flagged for waste, mismanagement, and fraud, raising fresh doubts as state leaders propose taxing billionaires to keep it afloat.

For years, audits and federal investigations have documented everything from improper payments to large-scale fraud schemes. State officials have acknowledged that fraud has reached alarming levels in some sectors...