The fallout from that, Laszewski said, would be even greater in HealthCare.gov states that have not expanded Medicaid eligibility to include most poor adults, meaning that hundreds of thousands of adults in big states like Texas and Florida would be left without affordable health insurance options that are available in states that expanded Medicaid and have their own exchanges.
"It does not understate it to say it would be an extraordinary mess, which would create one hell of a problem," he said. "Then the debate would move on to, 'Who broke it?' Because it would be broken, in spades."
Len Nichols, a professor of health policy at George Mason University, also questioned the political wisdom of attacking subsidies that go to the one group of adults "paying retail" for insurance. Nichols noted that poor adults in a little more than half the states can get Medicaid, at no cost to them, while employer-sponsored insurance is subsidized by a tax exemption for such benefits.
"Why would you want to turn 30 million people into opponents of your political positions?" Nichols asked, referring to the people now eligible for Obamacare subsidies.
But Tom Miller, a fellow at the American Enterprise Institute, scoffed at suggestions that a court-ordered end to the subsidies would be the end of the world.
"You can almost smell the napalm in the morning," Miller said sarcastically. "I would say, in fact, it's 'Apocalypse Not.'"
Miller said a ruling against the subsidies would prod Republicans and Democrats to negotiate a solution to the "good bit of disruption" that would be seen in the individual insurance market in HealthCare.gov states.
"What we'd likely see is efforts to liberalize and expand an alternative subsidy delivery system," Miller said. He also said that in the wake of a Supreme Court decision overturning the HealthCare.gov subsidies, the federal government could loosen standards on what would qualify as a state-run exchange, where the subsidies could be disbursed.