The nation's highest court again has the future of the president's signature health care law in its hands.

The Supreme Court will hear arguments Wednesday from opponents who say it's being wrongly implemented. The case is called King v. Burwell, and the plaintiffs say the federal government is breaking the law when it pays subsidies to people buying health insurance through the three-dozen states in the federal exchange.

Why? Because, they say, the language of the Affordable Care Act only calls for subsidies in states that set up their own exchanges. The law mandates that all Americans get insurance or face a penalty. To help achieve that goal, the federal government has paid subsidies to make the insurance premiums more affordable.

In a conference call with reporters, Democratic Senator Chris Murphy said that Congress always intended for the subsidies to apply to every state.

"The Affordable Care Act is built to spread subsidies all across the country, whether individuals are in state-based exchanges or federal-based exchanges," Murphy said. "The language of the statute makes that clear, but the design of the statute makes that clear, as well."

Murphy said a ruling striking down those subsidizes would mean millions of Americans would lose their health coverage -- and it would likely decimate the Affordable Care Act in those states. "States like Connecticut could survive, but unfortunately we represent the minority of states across the nation," he said.

Meanwhile, Connecticut's exchange, Access Health CT, has announced this: it's opening a month-long special enrollment period for those without insurance who only found out about the penalty for not having insurance when it came to file their 2014 taxes. That enrollment period will be in April.