WASHINGTON – A divided U.S. Supreme Court on Thursday turned back a conservative challenge that threatened to strip health insurance for millions of people in states like Texas that didn't set up their own state-base exchanges under President Barack Obama's signature health care law. The long-anticipated 6-3 decision is the second high-court victory for the Affordable Care Act, which extended federally subsidized health insurance to an estimated one million people in Texas, the state with the largest share of uninsured residents.