When Trump administration officials slashed the advertising budget for healthcare.gov, the Affordable Care Act s online marketplace, they said it was because of efficiency. Advertising, they said, was showing diminishing returns and was no longer an effective way to boost enrollment.

But research that the Department of Health and Human Services conducted and then distributed internally during President Barack Obama s tenure pointed to a very different conclusion.

It found that the ads work.

The research, summarized by documents that a Senate Democratic office provided to HuffPost, focused on the two most recent years of open enrollment for the Affordable Care Act. Like all such studies, it is not definitive. But its findings are consistent with outside studies that have similarly found advertising to be effective.

It also suggests that the decision to cut healthcare.gov advertising, which experts have already warned will depress enrollment, is another example of the Trump administration undermining Obamacare through neglect or outright sabotage .

Of course, maybe thats not surprising given that the Trump administration is simultaneously trying to wipe the 2010 health care law off the books.

Read the internal HHS research memo here.

The HHS research suggested that, combined, all advertising was responsible for about 37 percent of new enrollees signing up. That figure backs up prior assertions from Obama-era HHS officials, including Andy Slavitt , who was in charge of the Center for Medicare and Medicaid Services (CMS), and Lori Lodes, a who oversaw CMS outreach efforts and wrote about them for Vox .