Ask House Speaker Paul Ryan about the state of Obamacare and he has a ready response. “It’s in a death spiral,” he said Thursday at his weekly press conference. It’s a scary term, one that carries significant weight as the Ryan-led House Republicans prepare to take the first step towards repealing and replacing the law.But there’s one problem: Obamacare isn’t in a death spiral—at least not yet.It might sound like a dire rhetorical flourish, but to health care experts, “death spiral” has a very specific meaning: It’s what happens when premiums rise so much that young and healthy enrollees drop coverage in large numbers.