Donald Trump’s approach to health care could cause the number of uninsured Americans to skyrocket, yet another group of experts predicts. 

This time around, the warning comes from researchers with a relatively conservative outlook ― in other words, people generally sympathetic to what Trump, in theory, is trying to do.

A think tank called the Center for Health and Economy published a report on Thursday about the likely effects of Trump’s call to repeal and replace the Affordable Care Act, aka Obamacare. The Center is nonpartisan and includes board members from across the political spectrum. Its founder, Douglas Holtz-Eakin, once served as director of the Congressional Budget Office.

But Holtz-Eakin is also a longtime adviser to Republicans and frequent critic of the health care law. The Center’s start-up funding came from the American Action Forum, which bills itself as a “center-right policy institute.” 

Thursday’s report reflects that perspective, highlighting what many people ― and, in particular, many conservatives ― would consider the upsides Trump’s proposal to replace Obamacare with “something terrific.” Premiums for people buying coverage on their own would generally come down, the report says, while insurers would probably give beneficiaries access to more doctors and hospitals than the plans currently on the market do.

But there would be some big downsides too. Older people, as well as people with pre-existing conditions, would end up paying more for insurance. And many of them couldn’t get coverage at all. The plans available on the market would probably have some combination of even higher out-of-pocket expenses and big gaps in benefits. People relying on either federal assistance or federal programs for health insurance would see that help dwindle or vanish altogether.

As a result, the report says, the ranks of the uninsured would immediately swell by 18 million ― effectively reversing the historic expansion of insurance coverage that the Affordable Care Act has produced in its first three years. 

That estimate, to be clear, is very rough. Trump’s pronouncements on health care have been characteristically vague and contradictory. But he has vowed repeatedly to repeal Obamacare, calling it a “disaster,” and in March he laid out some principles for an alternative health care system. They echo ideas that many other Republicans have endorsed and, when it comes to insurance coverage, entail two basic sets of changes.

The first would be a total repeal of regulations that the health care law has placed on insurers. Today, insurers cannot deny coverage or charge higher premiums to customers they believe are likely to run up high medical bills. In addition, insurance plans must meet a set of minimum standards, which include a limit on out-of-pocket costs and benefits like mental health and maternity care that the law deems “essential.”

Trump would eliminate those regulations. In addition, he would allow insurers to sell policies across state lines, effectively undermining any state regulations designed to make insurers live by the same sorts of rules. These regulations tend to make insurance more expensive, since they force insurers to cover more services and sell to the very people likely to use them. That’s why they’ve pushed up premiums, on the whole. Rescinding them would make coverage cheaper ― but also less protective and harder to get.

The other big change Trump has in mind would involve government money and what happens to it. The health care law offers tax credits, worth hundreds or even thousands of dollars a year, to people buying coverage through the law’s marketplaces. It also offers an infusion of federal funding to states willing to make their Medicaid programs available to all low-income residents, as 31 states and the District of Columbia have already done. The law pays for these new expenditures through a combination of reductions in Medicare spending and new taxes, mostly on the wealthy and corporations.

Trump would wipe all of this off the books. And while he would offer a different form of assistance, by allowing people to deduct health insurance expenses from their taxes, it would mean less federal money to help people get coverage ― and a lot less help for the poor. On the federal ledger, the difference would show up as lower expenditures. In the streets, it would show up as more hardship for people who need medical care.

Financial distress would become more common, as could preventable deaths.

During the presidential primaries, Trump was the one Republican who went out of his way to say he would not let that sort of thing happen. During a February rally in New Hampshire, for example, Trump said, “We do need health care for all people. What are we gonna do, let people die in the street?”

But actually protecting people from crippling medical bills, and making sure they have access to health care, turns out to be complicated. It requires making tough decisions about trade-offs between cost, quality and access; building political coalitions and overcoming special interests; and committing taxpayer resources for what is arguably a public good.

These are not things that Trump seems interested in, or capable of, doing ― as this latest report shows.