Making health insurance available and affordable to millions of people who buy their own coverage was a key goal for backers of the federal health law known as Obamacare. But if the Supreme Court strikes down the insurance subsidies of millions of Americans who rely on the federal insurance marketplace, it could leave many worse off than they were before the law took effect, say experts. "The doomsday scenario could materialize and it does impact everyone" — those getting subsidies, as well as those paying the full cost of their plans on the individual market in states using the federal exchange, said Christopher Condeluci, an attorney who worked for Iowa Republican Sen. Charles Grassley on the Senate Finance Committee staff during the drafting of the law.