Protections for people with pre-existing conditions would vanish. Initiatives to improve hospital quality would stop. Rules for calorie counts at restaurants would no longer be in force. And oh, yeah, something like 20 million people would lose health insurance. Those are just some of the likely consequences if the federal courts rule in favor of a lawsuit challenging the Affordable Care Act and decide — as President Donald Trump said he hopes they will — that the entire law has to come off the books. The lawsuit comes from 20 Republican state officials. Although it prevailed in a federal district court late last year, even conservative experts say the case is weak and begging for reversal ― either at the U.S. 5th Circuit Court of Appeals, which will consider it next, or the Supreme Court, should it get that far.

Bloomberg via Getty Images President Donald Trump reportedly instructed the Justice Department, which already endorsed a lawsuit against the Affordable Care Act, to support calls for invalidating the whole statute.

But nothing is certain, and on Monday the Justice Department, which already endorsed the plaintiffs’ arguments, told the 5th Circuit that it also supported their preferred remedy: invalidating the entire program. The decision came from the White House, with Trump overruling several skittish advisers, according to reports that first appeared in Politico. Trump has since promised an alternative program that would provide better, cheaper coverage, but Republicans have never devised such a plan. In all likelihood, the kind of ruling Trump now seeks would require complete dismantling of the Affordable Care Act, down the last statutory clause and last appropriated dollar. The Effects Would Touch Every Kind Of Insurance The most obvious and understood changes would affect protections for pre-existing conditions, which Trump keeps insisting he and Republicans are committed to preserving. In reality, requirements that insurers sell to anybody, regardless of medical condition and at uniform prices, would come off the books if the Affordable Care Act went away. So would requirements that all policies cover 10 “essential benefits,” including mental health, maternity and prescription drugs. But it’s not just insurance rules that would disappear. Money would too. Today Americans who buy insurance on their own can get tax credits if their income is below four times the poverty line (about $100,000 a year for a family of four). Those credits effectively discount premiums by hundreds and sometimes thousands of dollars a year ― and they would be gone if the Affordable Care Act comes off the books. A complex chain of events would likely follow. The number of people buying insurance on their own would drop from 19.4 million to 12.6 million, according to projections that the Urban Institute published this week. And it’s not as if those 12.6 million would have coverage equivalent to what’s available on HealthCare.gov today. The plans would be cheaper, but only because they had big benefit gaps and weren’t even available to people with pre-existing conditions. Some people would save money, sure — mostly those who are healthy and able to stay that way.

Medicare payment rules, fraud and abuse prohibitions, Indian Health Service reforms, the Medicaid expansion ... all would fall by the wayside. Timothy Jost, law professor emeritus, Washington and Lee University

The most profound effect on coverage would be on Medicaid, the government-run health program for the poor. Thirty-six states plus the District of Columbia have expanded the program to cover residents with income below or just above the poverty line. For millions of people, it has meant less financial hardship, better access to care and improved health, research has shown. Funding comes largely from the federal government, and it too would vanish with a court ruling wiping out the Affordable Care Act. “States would have to quickly decide whether to continue covering some or all of these adults with their own funds,” said Judy Solomon, a senior fellow at the left-leaning Center on Budget and Policy Priorities. “It’s doubtful many would be able to do that.” In some states, cuts would happen automatically because the executive actions or laws authorizing expansion call for restoring the old, pre-expansion eligibility standards if the extra federal funds stop flowing. Taking all of this into account, enrollment in Medicaid would drop from 68.6 million to 53.2 million, by the Urban Institute’s reckoning. Medicaid programs would have to change in other ways as well, because the Affordable Care Act introduced enhancements like new home-based care options for the disabled and elderly. These initiatives would lose their federal authorization, leaving decisions about whether to continue the programs in the hands of cash-strapped state officials. Sponsors of private employer plans, through which roughly half of all Americans get insurance, could once again impose annual or lifetime limits on benefits, since it’s the Affordable Care Act that made such limits illegal. That could really hammer patients with rare forms of cancer or congenital conditions like hemophilia, for which treatments can easily exceed a million dollars per year or sometimes even per month. And then there is Medicare ― yes, the same program that so many Trump supporters cherish and that Trump pledged, over and over again, never to touch. The Affordable Care Act bolstered Medicare in several ways, most obviously by gradually eliminating a gap in prescription drug coverage, known as the doughnut hole, that left seniors on the hook for especially high out-of-pocket costs. Without the Affordable Care Act in place, the doughnut hole would open back up. The Effects Would Be Difficult For Courts To Sort Out This is one of the many areas in which undoing the law would be a lot more complicated than it sounds. The original plan on Medicare, under the Affordable Care Act, was for the doughnut hole to close in 2020. Last year, Congress passed a law that moved up the timeline so that it would close in 2019. But that legislation was a modification of the Affordable Care Act, and it’s not clear what would happen to a law modifying a law that, years after enactment, the courts determine is become unconstitutional. It sounds like something out of a Star Trek episode with a rupture in the space-time continuum, but legal experts HuffPost consulted were genuinely uncertain how officials would sort it out. “It’s almost impossible to wrap your brain around how this would actually work,” said Sabrina Corlette, a research professor at Georgetown University.

It’s almost like you’d need a special master to go through these changes, line by line, to figure out what’s constitutional and what’s not. Sabrina Corlette, research professor, Georgetown University