Both proponents and opponents of Obamacare are taking credit for the surge in sign-ups on in the most recent open enrollment period.

The Trump administration claimed credit for the efficiency and smart decision-making that led to more than 8.8 million sign-ups and counting, while pro-Obamacare groups credited the results with Obamacare's staying power and urged Republicans to abandon efforts to undo the law.

"The Affordable Care Act is working, and people’s lives are improving because of it," said Brad Woodhouse, director of the pro-Obamacare group Protect Our Care. "Despite widespread sabotage by the Trump administration ... these numbers prove that people want and need the affordable, quality health coverage the ACA provides, they rely on it for health and financial peace of mind and any further attempts at sabotage will be met with severe resistance. It’s time for the GOP to abandon efforts to take away people’s healthcare.”

Lori Lodes, who ran Obamacare outreach under the former administration and now works for a group called Get America Covered that helps people enroll, said that the demand "speaks volumes — proving, yet again, the staying power of the marketplaces."

"It is time for Republicans to stop their campaign to sabotage our nation’s health care system, and to work to make high quality, affordable health insurance available to all Americans," said Rep. Frank Pallone of New Jersey, the top Democrat on the House Energy and Commerce Committee. Sen. Ron Wyden of Oregon, the top Democrat on the Finance Committee, brought attention to the numbers on social media.

The figures came out only a day after Congress passed a tax bill that will repeal Obamacare's individual mandate penalties that obligate Americans buy insurance or pay a fine. President Trump has vowed to repeal the law and has called it "dead."

The enrollment numbers surprised may different observers of the law who had expected a significantly lower turnout compared to where it was under the Obama administration. The Trump administration had cut the enrollment period in half, from 90 to 45 days, and had slashed funding on advertising and outreach.

While Trump continues to make it clear he opposes the law, Seema Verma, administrator for the Centers for Medicare and Medicaid Services, framed the outcome as the result of her agency's efficient use of government funding and as a sign of how staffers had created a strong, well-run website. She added that during the early years of Obamacare, the site was plagued by "website failures that were commonplace."

CMS sent a release noting that had targeted customers through digital advertising and through email reminders, connecting customers with brokers and agents. In total, the agency spent $10 million on marketing and outreach, compared to $100 million last year under former President Barack Obama.

“Our goal from the beginning was to empower patients across the healthcare delivery system and make sure that Americans who chose to enroll in the exchanges had a good customer experience while making enrollment more cost efficient, and the results show that we accomplished our goal,” Verma said in a statement.