Many have dismissed Rick Scott’s lawsuit against the Obama administration over Medicaid funding as meritless, but the Florida governor might actually be doing everybody a favor. The case could help answer a huge constitutional question left over from the 2012 Supreme Court decision on Obamacare.

That’s right—there’s still more of the landmark ruling that upheld President Obama’s signature domestic policy to pick over.

Scott alleges that the administration is illegally trying to force Florida to expand Medicaid under the health care law by threatening to cut off about $1 billion from a separate federal funding stream which helps hospitals that provide uncompensated care to uninsured people.

The court ruled in 2012 that the federal government couldn’t threaten to cut off all of a state’s existing Medicaid funding, which would wreck any state budget, to compel states to accept Obamacare’s Medicaid expansion. It was unconstitutionally coercive; Chief Justice John Roberts called it “a gun to the head” in his decision.

“The Supreme Court said it’s illegal to be coercing a state to expand Obamacare,” Scott said Wednesday after a meeting in Washington with Health and Human Services Secretary Sylvia Mathews Burwell (they did not resolve the impasse). “That’s exactly what they’re doing.”

But what Roberts didn’t say in his ruling was where exactly the line is that separates the federal government’s lawful discretion to persuade states to participate in a program from such illegal intimidation. He explicitly avoided creating a definitive test for it.

“We have no need to fix a line either,” Roberts wrote after referencing a prior case in which the Court declined to delineate between persuasion and coercion. “It is enough for today that wherever that line may be, this statute is surely beyond it.”