Despite the repeated inability of Republicans to repeal the Affordable Care Act in its entirety, some in conservative and libertarian circles are attempting to find ways to unravel the law piece by piece.

Michael Cannon, director of Health Policy Studies at the libertarian Cato Institute, has been at the forefront of one attempt to dismantle the ACA, one that has been gaining steam. He argues that Congress meant for the subsidies to help individuals purchase health insurance through state (not federally) created exchanges. “If a state opts instead for a federal exchange, as more than 30 states have, the IRS has zero authority to penalize employers there,” Cannon wrote last month.

That means, according to Cannon, no penalty for employers who do not offer health insurance or the individual mandate that individuals must purchase insurance. In short, “Obamacare” comes undone.

But some argue that Cannon’s interpretation is misguided at best, if not flat out wrong.

Jonathan Gruber, the MIT professor who helped write former governor Mitt Romney’s Massachusetts health care law, as well as the Affordable Care Act, told Mother Jones that Cannon’s theory is a “screwy interpretation” of the law.

“It’s nutty. It’s stupid,” he says. And beyond that, “it’s essentially unprecedented in our democracy. This was law democratically enacted, challenged in the Supreme Court, and passed the test, and now [Republicans] are trying again. They’re desperate.”

That was a cue for Cannon to say enough’s enough, issuing this challenge today: