Karen Ignagni was the woman who could have killed Obamacare. Instead, the nation's top health insurance lobbyist helped President Barack Obama to pass his sweeping health reform. And she became emblematic of the compromises and controversies that still define the Affordable Care Act today. Ignagni announced her departure from America's Health Insurance Plans on Thursday. After more than two decades as a D.C. lobbying powerhouse, she's going to run EmblemHealth, a big New York insurer. She leaves at a watershed moment. Next month, the Supreme Court in King v. Burwell will decide whether people in states using the federal health exchange can keep getting government subsidies to buy insurance, or whether the financial assistance should only be allowed in states running their own Obamacare markets.