The U.S. Treasury Department announced today, Sept. 10, that since the Affordable Care Act was passed more than a decade ago, nearly 50 million people have purchased health insurance through the marketplaces it created. The department’s data shows that one in seven Americans was or is covered by the law. And since President Biden took office in January 2021, 18.2 million Americans have received ACA insurance for the first time.

The increase in enrollment since 2021 is due to an expansion of premium tax credits by the Biden administration, which now includes individuals and families with household incomes up to 400% of the federal poverty level, which is $58,000 for an individual and $120,000 for a family of four.

The ACA has had a turbulent history since its passage in 2010. Republicans have repeatedly called for the law to be repealed. Yet the ACA is more popular today than ever. According to KFF, over 60% of the public has a positive opinion of the law.

The ACA is a comprehensive reform law passed by Congress in 2010. It increases health insurance coverage for the uninsured and introduces a wide range of reforms in the health insurance marketplace, as well as an expansion of Medicaid, the public insurance program that provides health insurance coverage to low-income families and individuals. Importantly, the ACA allows individuals who may have been uninsured due to pre-existing conditions or limited financial resources to secure affordable health insurance plans through the law’s health insurance marketplaces.

The law has its critics. They point to certain deficiencies in its conception and implementation. In fact, in the first years of the Obama administration, insurers left their insurance companies in droves and premiums rose considerably. The ACA was nowhere near as popular then as it is today.

Under the Trump administration, the number of ACA insured people fell while the number of uninsured increased by more than two million. After unsuccessful efforts to overturn the ACA, the president issued executive orders to “improve ACA market dynamics.” In the second half of Trump’s term, the ACA exchanges actually stabilized as insurers returned and the rate of premium growth slowed.

When Biden took office, he sought to expand the ACA program and reverse some of the changes introduced by the Trump administration that had shrunk it. As a result of the premium tax credits mentioned above for eligible insureds and a provision in the Inflation Reduction Act of 2022 that provides expanded subsidies for plans that sell insurance on the ACA exchanges, record numbers of Americans are now enrolled in health insurance plans related to the ACA.

The ACA has thus achieved its main goal of reducing the number of Americans without health insurance. The rate of uninsured people is currently at a historic low of 7.7% nationwide.

Thanks to the ACA, 50 million people now have health insurance. On the campaign trail, Harris touted the successes of the administration she served in, including strengthening the ACA. She also wants to expand on those measures and broaden the reach of the Medicare drug pricing provisions in the IRA.

The perennial problem for Republicans who wanted to repeal the ACA is that the law contains provisions that are popular with voters, such as guaranteed health insurance with a community rating for people with pre-existing conditions, subsidies for people who buy health insurance on the government-run exchanges, and the ability for people under 26 to continue to be covered by their parents’ insurance.

Accordingly, it is very unlikely that Trump will try to overturn the ACA if he wins the election in November. It is far more likely that he will try to reform the ACA and make it what his allies are demanding: a streamlined program in which individuals have control over the ACA subsidies they qualify for, rather than the government dictating what benefits must be included in the insurance packages purchased on the marketplaces.