President Obama's healthcare law, struggling to survive its botched rollout, now depends more than ever on insurance companies, doctor groups and hospitals — major forces in the industry that are committed to the law's success despite persistent tensions with the White House. Many healthcare industry leaders are increasingly frustrated with the Obama administration's clumsy implementation of the Affordable Care Act. Nearly all harbor reservations about parts of the sweeping law. Some played key roles in killing previous Democratic efforts to widen healthcare coverage. But since 2010, they have invested billions of dollars to overhaul their businesses, design new insurance plans and physician practices and develop better ways to monitor quality and control costs.