INKSTER, Mich. ― Cassandra Barnes was barely conscious and mumbling incoherently when her sister and son discovered her sprawled across the bed. Barnes had overdosed on heroin and her vital functions were slowing. By the time her sister and son got her to the hospital, doctors had to order warming blankets just to get her temperature back up to normal.

Barnes had overdosed before, but had never come so perilously close to death or let her family see her in that state. “I didn’t want them to find me like that,” she told HuffPost this summer, four years after the fact.

At her sister’s suggestion, Barnes enrolled in an addiction program at the Western Wayne Family Health Centers, a group of federally funded clinics scattered across the lower-income suburbs of Detroit.

Western Wayne’s outpatient program for substance abuse uses an expert-recommended, two-pronged approach: medication that satisfies the cravings of addiction without creating the associated high, along with counseling and medical care to treat the underlying conditions that foster substance abuse.

Crucially, Western Wayne also helps patients enroll in Medicaid if they are eligible. And Barnes was, because Michigan is among the states that have expanded their programs through the Affordable Care Act.

Barnes finally got clean, after a few months. She also started getting treatment for her chronic conditions that had been making it difficult for her to work. “I wasn’t even dealing with my diabetes because I didn’t have insurance to pay for it,” she said.

Today she splits her time between helping with her 3-year-old granddaughter, who calls her “Gigi,” and searching for a job. She is looking for something in customer service or retail, but at 63, she’d also love a chance to share some of her wisdom about addiction and recovery by working as a “peer coach.”

“I’m so thankful, and I say to people, ‘If I could do it, you could do it,’” Barnes said. “I always like to tell my story.”

Hers is a story of personal triumph. It’s also a story about policy success, because it’s possible she wouldn’t be where she is today without the Medicaid expansion. But that success won’t last, and future substance abuse patients might not be able to get the care that Barnes has, if the Republican crusade against “Obamacare” doesn’t relent.

What The Medicaid Expansion Has Meant For Opioid Treatment

Under the Medicaid expansion, states can use extra federal funds to open up their programs to all residents with incomes below or just above the poverty line, instead of limiting eligibility to targeted groups ― such as young children and pregnant women ― as they have done in the past. More than two-thirds of the states have taken advantage of the opportunity, as Michigan officials agreed to do in 2014.

The expansion is the single biggest reason that, since the law’s full implementation, the number of people without insurance has fallen to historic lows. People who get Medicaid through the expansion are likely to end up more financially secure, have better access to medical care, and end up in better health generally, research has repeatedly shown.

But perhaps nowhere is the impact more vivid than in the fight against the opioid epidemic, which has taken nearly half a million American lives over the past two decades. Today, Medicaid underwrites care for more than one-fifth of all Americans receiving treatment for substance abuse, more than any other single program.

And that money matters. Multiple studies have shown that in states that expanded Medicaid eligibility, people with addiction were more likely to get treatment and less likely to die. One study found that prescriptions of naloxone, a potentially lifesaving drug to treat overdoses, were substantially higher in expansion states than non-expansion states.

One reason the expansion has made such a difference is that it has dramatically changed the finances for organizations and programs that serve low-income patients, including those with substance abuse problems. The Medicaid expansion is meant to allow higher funding to continue indefinitely, giving the providers of care ― and the state and local authorities that fund them ― confidence to make long-term investments in new facilities and personnel.

In the past, experts note, local and state governments have sometimes declined to spend money available to them through public or private grants, precisely because they worried that the money would run out and they’d be stuck with programs that couldn’t sustain on their own.

“States end up in this defensive crouch,” Keith Humphreys, a Stanford professor and expert on substance abuse programs, told HuffPost. “They think, wait a minute, if we build a building, buildings need maintenance, light, heat ― where’s the money going to come from when the grant ends?”

Western Wayne is a perfect example of what a difference the Medicaid expansion can make. Jeren Stepp, the chief financial officer, says that in 2013 about half of its patients had no insurance. Now, thanks to the Medicaid expansion, that figure has fallen to about 10%.

“For our margins, that’s a big deal,” Stepp said, “because now we have the autonomy to fund other programs or even talk about growing and expanding.”

And in fact that’s precisely what Western Wayne has been doing. It opened its third clinic in 2014, once it was clear the Medicaid expansion was going forward, and it’s in the process of opening a fourth. It’s hired new therapists and a new psychiatrist, and created a new integrated behavioral health program. It’s also built out a new dental service, meeting a need that rarely gets attention in the media but that makes a huge difference in people’s ability to join the workforce and, more generally, engage in everyday life.

“Knowing that a much greater proportion of our patients got coverage via Medicaid or Healthy Michigan Plan ― and a greater pool of potential patients in our target group now had access to coverage ― we were able to make decisions to add services,” Lisa Rutledge, Western Wayne’s director of special projects, told HuffPost. “We would not have almost 600 patients in MAT [medication-assisted treatment] currently without that coverage.”

What Repealing The ACA Would Mean For Opioid Treatment

In a rational world, this record of success would inspire enthusiasm and support for the Medicaid expansion ― not just from Democrats, who have always believed in government-sponsored health care, but also from Republicans, who have proclaimed over and over again their determination to stop the opioid epidemic.

Just last week, President Donald Trumpboasted that his administration “is determined to use every resource at our disposal to smash the grip of addiction.”

Trump was speaking at a press conference to announce $2 billion in new grants to state and local agencies. The money, which came from a bipartisan bill that Congress passed and Trump signed last year, is meant to make the kind of treatment they offer at Western Wayne even more widely available than it is now. It will almost certainly help a lot of people, and it’s a credit to its sponsors ― most of whom, regardless of party, presumably feel genuine compassion for their constituents battling substance abuse.

But Trump and his allies are also in the middle of a campaign to undermine the Medicaid expansion, as part of their war on President Barack Obama’s signature policy achievement ― an effort that’s been one of the party’s defining crusades since the ACA became law.