Harris in February granted “conditional approval” of the ownership change from the Daughters to Prime — provided Prime agrees to a 78-page agreement filled with costly conditions. For the next 10 years, Prime would agree to keep all the hospitals open. It must spend $150 million on capital improvements in three years, assure the full pension benefits of retirees and current employees, and invest $350 million in seismic retrofitting. . . This convoluted deal is easier to understand in the context of union politics. The powerful Service Employees International Union/United Healthcare Workers West has been harshly critical of the sale to Prime, which it accuses of profiteering. By contrast, one of its rival unions, the California Nurses Association, has backed the sale as a way to save the hospital system.