This telemarketer had rotten luck. Of all the random phone numbers someone shilling for a shady insurance company could ring up, hers had to lead to the Minnesota home of a formidable health care expert — Andy Slavitt.

Slavitt, the founder of the nonprofit advocacy group United States of Care, is a former Twin Cities health care executive who also served as acting director of the federal Centers for Medicare and Medicaid. In health policy circles, he’s best known as the fixer brought in after’s glitch-plagued 2013 debut.

So the recent phone pitch for a dubious insurance product was met with hard questions. The out-of-her-depth telemarketer put her supervisor on the line. He replied to Slavitt’s queries with escalating falsehoods — among them, that annual caps on insurance benefits banned under the Affordable Care Act are now legal (they’re not). When called out, he responded with a crude, conversation-ending insult.

Slavitt shared the episode on Twitter not just to alert consumers about phone scams, but to send a timely reminder about the minefield health insurance consumers faced before the 2010 Affordable Care Act’s passage — and could face again as the law’s fate once more hangs in the balance.

Oral arguments were heard Tuesday in the Fifth Circuit Court of Appeals in a lawsuit known as the “Texas case.” At issue is whether Congress’s 2017 move to eliminate the health law’s financial penalty for failing to buy health insurance renders the entire law unconstitutional. A group of Republican state attorneys general led by Texas’ top lawyer argue that it does. The case appears headed to the U.S. Supreme Court, where justices have already upheld the law twice against other challenges.

The health law could be struck down in its entirety if the plaintiffs succeed. If that happens, the number of uninsured Americans could rise by nearly 20 million.

Financial assistance to help consumers buy private insurance would be gone. More than 61,000 Minnesotans currently receive this help, getting an average of $307 a month in aid.

Gone, too, would be billions in federal aid to help states cover needier people through the expanded Medicaid program. The loss to Minnesota: about $2.25 billion a year for the state’s medical assistance and MinnesotaCare programs.

Slavitt’s phone fracas is a reminder of what else could be lost with the law’s demise: its landmark insurance regulations, which are especially helpful for those who buy insurance on their own instead of getting it through an employer. Early retirees frequently fall into this group.

The law’s safeguards, such as standardizing the benefits that must be covered, protect consumers from a policy’s fine print. The dangers that often lurked there before the law’s passage were not limited to dubious policies sold over the phone. Instead, even reputable companies’ policies could include hard-to-understand exclusions for certain kinds of care or medications, as well as other loopholes that could leave even savvy consumers stuck with a pile of big medical bills.

“You used to have be smarter at reading the fine print than the insurance companies were at writing it,’’ Slavitt said.

Overturning the Affordable Care Act would tilt the insurance marketplace back in favor of those who write the fine print. Scammers will come out in droves to take advantage of it, and many of their tricks could be legal.

Not everyone can fend them off as easily as Slavitt. The law’s consumer protections are still vital. Tearing them down is just one of many reasons this wrongheaded legal challenge will harm consumers, not help them.