WASHINGTON—Borrowing a word from Democrats, a new White House report says changes made to the Affordable Care Act under President Trump didn't amount to "sabotage."

Due out Friday, the report from the Council of Economic Advisers says Obama-era subsidies that help low- and middle-income customers pay their premiums will keep HealthCare.gov afloat even if some healthy people drop out or seek other coverage because of Trump's changes. Nearly 90 percent of customers get taxpayer-provided assistance.

The report looks at three big changes under Mr. Trump that affect former President Barack Obama's health care law. They are congressional repeal of the law's unpopular fines on people who go uninsured, "association health plans" for small businesses that can be marketed across state lines, and low-cost short-term health insurance that doesn't have to cover pre-existing conditions or basic benefits like prescription drugs.

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"These reforms do not 'sabotage' the ACA but rather provide a more efficient focus of tax-funded care to those in need," the report says. The council is a White House agency that advises the president.

Larry Levitt of the nonpartisan Kaiser Family Foundation said less regulation "isn't automatically an act of sabotage," but Mr. Trump has made clear his hostility to "Obamacare."

"The president seemed to take pride in undermining the ACA, but now his administration is resisting the argument that they have undermined the health law," said Levitt, who reviewed the report for AP. "They can point to benefits of deregulation, but will also have to live with the costs, which include higher premiums for middle-class people with pre-existing conditions."

The report comes as House Democrats under Speaker Nancy Pelosi, D-Calif., are moving to shore up the ACA, including trying to undo some of Trump's insurance changes. Although such a rollback seems unlikely to succeed under divided government, there has been bipartisan support for measures that would help reduce premiums and guarantee coverage for pre-existing conditions. Restoring the ad budget for HealthCare.gov slashed by Mr. Trump is also a possibility.

Democratic White House hopefuls are seizing on health care as an issue, with some pushing for a government-run system that would cover all Americans and replace "Obamacare."

About 10 million people continue to get private insurance through the ACA's subsidized markets, or exchanges, and another 12 million are covered by its Medicaid expansion. The GOP's drive to repeal the ACA in 2017 fell flat, and Democrats effectively blocked another try by gaining control of the House.

Casey Mulligan, chief economist for the White House council, said it turns out that the penalty for people going uninsured wasn't really essential for the Obama health law to function. The subsidies were more important.

"Removing the tax penalty and opening up more affordable options was able to save taxpayer dollars, give families more choice, without destabilizing the exchanges," he said.

The report didn't address constitutional arguments in a Texas court case against the ACA brought by red-state officials. But its economic analysis could have a bearing on that case.

The plaintiffs contend that the whole law was made unconstitutional by congressional repeal of the fines on the uninsured. A federal district court judge agreed, and that ruling is on appeal. The Justice Department has said in connection with the case that it will no longer defend the law's protections for people with pre-existing conditions.

Now the White House report undercuts the notion that the tax penalties at issue in the case are central to the health law. Officials at the Council of Economic Advisers said they're not policymakers or lawyers, but economists.

The report also claims $450 billion in consumer benefits over the next 10 years based on broader availability of less costly insurance options, reduced taxpayer spending on subsidies, and the cancelled fines. But it acknowledges that premiums will go up for some middle- and upper-income consumers.

Kaiser Foundation analyst Levitt said $450 billion seems high to him.