"That probably dampened this year's enrollment by about a million and a half people," Sebelius said. 

In 2014, the GOP-controlled Congress blocked funding to help insurance companies offset the cost of covering people with pre-existing conditions, she added. 

Now, Trump's threat of ending cost-sharing reduction payments to insurers is creating uncertainty in the individual marketplace, Sebelius said.

Some large insurers, including Aetna and Humana, have already said they will not participate in the health exchange market in 2018 due to the uncertainty. Blue Cross and Blue Shield of Kansas City has also pulled out. 

"What a number of the companies have said is, 'If we don't know if we're going to get paid back, one of two things will happen,'" Sebelius said. "'We will either drop entirely out of the marketplace because we cannot afford to take that kind of hit. Or we will raise our premiums substantially to cover that cost that we must by law offer to consumers.' Either way, that's a very disastrous thing for health consumers."

Republicans in Congress — if they really don't want to sabotage the ACA — can force Trump to keep making the cost-sharing reduction payments to insurers, and can also work with Democrats to fix the current law's problems, she said.

"They could immediately say, 'We want the law to work the way it is,'" Sebelius said. "'This is the law, let's enforce the law.'" 

PBS last month reported that the Trump administration had ended ACA contracts, cutting access to assistance for shoppers for health coverage on the exchanges and reducing the number of places they can go for help. 

In 18 cities where people looking for help in buying coverage from the exchanges were formerly able to go to certain libraries, businesses and urban neighborhoods to find help signing up for coverage, that help is no longer available.

The PBS report points out that community groups, which learned of the move from contractors, say that the contracts' ends will make it even more difficult to enroll the uninsured and help people who are already covered re-enroll or shop for a new policy.

It compounds a problem that already exists, with confused consumers worrying about an enrollment period that's been cut in half—from 90 days to just 45—and beginning Nov. 1 and ending Dec. 15. 

There are also allegations that the administration has undertaken an extensive public relations campaign against the ACA, using taxpayer funds that were intended to promote enrollment in the program to denigrate its quality and effectiveness.

A Daily Beast report cites "sources at various agencies and on the Hill" for information on the PR effort and changes to websites that formerly provided information and assistance on the ACA and how to sign up.

The Department of Health and Human Service's own website is delivering criticism of the ACA, not information on the ACA and ways to sign up for health care — and changes have been made on healthcare.gov as well relating to consumer education.

"Under the 'Get Answers' section of the site," the report says, "there no longer is a 'Cost & Savings' tab that allows visitors to find out where to find prices, if they have to pay penalties, or if they qualify for savings." 

The administration's efforts have prompted legal experts and Congressional Democrats to ask government agencies "to investigate whether the administration has misused funds and engaged in covert propaganda in its efforts to damage and overturn the seven-year-old health care law." 

"There's a clear pattern of the administration trying to undermine and sabotage the Affordable Care Act," Elizabeth Hagan, associate director of coverage initiatives for the liberal advocacy group Families USA is quoted in the PBS report saying. Hagan adds, "It's not letting the law fail, it's making the law fail."