The law contained a carrot to force the states to set up exchanges. The congress assumed that American's would demand our state governments to give us free stuff. So they decreed that ONLY citizens who signed up through a STATE exchange would qualify for the government subsidy.

Since most American's didn't want it in the first place and wanted it less once they passed it so we could read it the states didn't build exchanges. Then the government said "Free stuff for all!!!"

Of the states that built exchanges most failed epically. The Oregon exchange never successfully signed up a single person.

If the court rules against the Obama administration this should end the ACA and create an amazing nightmare since the subsidies are managed by the IRS