When the democrat Congress enacted ObamaCare, it wanted to force reluctant Governors to set up their own healthcare exchange. Thus, they included language within the bill that persons are eligible for subsidies for healthcare coverage only if they are in “an exchange established by the state.” The alternative to “an exchange established by the state” is that for those states that fail to enact an exchange, individuals are relegated to the federal exchange.
Now that many Governors have stood up to President Obama and failed to enact an exchange, as in Ohio, the language of the law has backfired, precluding subsidies for individuals in many states.
That issue will be decided by the US Supreme Court tho coming term. If the Judges apply the law as plainly written, ObamaCare will turn out to be even worse than anyone initially predicted.
Read an in-depth New York Times article on the matter here.