After more than half a decade, the Affordable Care Act has never become popular in spite of repeated claims from liberal pundits and Democrats that a dramatic shift in opinion was always behind some new horizon. In fact, the law has arguably been a significant drag on the Democratic party for four straight election cycles.

Now as a result, we face the almost unprecedented reality of a major law being repealed. To understand how the law never became popular, we need to only understand the two artificial constraints Obama placed on his signature law back in 2009 which doomed it.

The whole story of the Affordable Care Act is long and complex. Early on, it was unpopular largely because of conservative campaigns against it and a clever Republican strategy to deny the law bipartisan support, making Democrats solely own it. But no amount of negative messaging would have worked in the long run, had the law delivered the results it promised.

The law’s continued lack of support, after being in effect for years, must be attributed to its failure to deliver. And the law failed to deliver because of these two constraints.

The first was Obama’s decision to cut secret deals with healthcare industry CEOs—in other words, his commitment to backing a plan the industry could support. These deals to gain industry backing meant the law couldn’t include the best and most proven ways to reduce health care prices, such as single payer, all payer, a public option, direct price negotiations, etc.

As a result, the law’s “cost control measures” relied on unproven or discredited free market ideas. These measures would supposedly reduce costs for regular people by “increasing their skin in the game” via high deductibles, narrow networks and an individual mandate compelling many people to buy insurance they legitimately couldn’t afford.

Obama’s second fateful decision was to promise the law would be deficit neutral and cost only $1 trillion over a 10-year budget window. This was idiotic on multiple levels. First, the law was only kept under $1 trillion with silly accounting gimmicks that involved Democratic Senators steadily shifting spending to a later date, so the claim had little real credibility. That said, the total amount shouldn’t really matter if it is also deficit neutral overall—the goal should either be to stay below a set amount or be deficit neutral, but having both goals created real confusion with voters.

Despite all of the administration’s accounting maneuvers and its relentless focus on these goals, most Americans ended up believing the law will increase the deficit anyway. Most importantly, this was a terrible decision because there is no way to provide what Obama promised for $1 trillion.

You can’t achieve both goals and get real universal coverage

It would have been possible to provide decent coverage for all of the uninsured for $1 trillion via a single government-run insurance plan, but that would have required real progressive cost controls the industry CEOs opposed. It even would have been possible to give all of the uninsured decent coverage without upsetting the healthcare industry, if Democrats were willing to just throw enough money at it.

Alternatively, you could keep the industry happy and spend only $1 trillion providing decent coverage to only some subgroups of the uninsured. However, you can’t provide decent universal coverage under these two constraints.

Instead of scaling back his promise when this became obvious, Obama thought Democrats could just lie about what the law really does and hope no one would notice. Instead of paying to provide universal, affordable coverage, Democrats merely claimed they created “universal coverage” because they mandated everyone buy coverage, even if they couldn’t really afford it. Not surprisingly, people noticed, as this great article in The Atlantic documents.

For many, the coverage the law provided was not affordable despite the promises. In fact, there are nearly as many people who are paying the individual mandate penalty (8 million) as there are who bought coverage on the Affordable Care Act exchanges (12.7 million). That is a policy disaster. And even among people who did buy coverage on the exchanges, there are a decent number of young or relatively healthy people who have a legitimate reason to feel the law made them worse off, due to increases in premiums/deductibles for plans they can’t afford to use.

This is not to say the law didn’t help anyone. The expansion of Medicaid did truly help many people. But people don’t judge the law by weighing every single plus and minus; they judge it by whether it lived up to its promise, and the Affordable Care Act did not.

There are millions that can make a strong case the Affordable Care Act made them worse off either because they have new “coverage” they can’t afford, saw higher premiums, or are paying a new penalty. You also have millions of people you could argue are better off but legitimately feel betrayed because they did not get what was promised.

Understanding the unpopularity of Obamacare is critical for progressives shaping a response to the Republicans’ eventual “repeal and replace” plan or any other law the newly empowered GOP pushes for. What people care about is whether a law lives up to its promises.

Trump actually made a lot of significant and positive sounding healthcare promises during the campaign to ensure coverage and reduce costs. Democrats should ensure no one forgets these promises. Even though most liberals never believed any of these Trump campaign promises, there are millions of regular voters who did—voters that can be turned against him.