Are tea leaves healthy? For now, reading them is all Americans can do to determine what will become of the Affordable Care Act. In oral arguments before the Supreme Court this week, two conservative justices tipped their hand that their votes could swing either way. A strict interpretation of tax-credit rules could gut the law, causing millions to lose coverage. That would impact the two-thirds of states without their own health-care exchanges, leaving some scrambling for makeshift solutions just in case.