Former President Barack Obama and other high-profile Democrats are on a social media blitz to remind people to sign up for health insurance through the Affordable Care Act before the open enrollment period ends in most states on Saturday.

Sign-ups are lower this year, and Democrats are blaming changes enacted by President Donald Trump and Congress that took effect this year. The Trump administration also scaled back the health law's advertising budget by 90 percent to $10 million last year, which was expected to impact enrollment in the ACA, commonly known as Obamacare.

House Minority Leader Nancy Pelosi and Sens. Elizabeth Warren and Bernie Sanders are trying to fill in the gap, along with other Democrats. They urged people to enroll for health coverage over the past few days. The biggest push seemed to come from the former president, who posted a 90-second video on social media Monday calling on people to sign up. Former first lady Michelle Obama reposted her husband's ad on Instagram, Twitter and Facebook.

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Democratic Gov.-elect Gretchen Whitmer of Michigan posted a video Tuesday on Twitter. Sign-up rates for Obamacare in Whitmer's state are down 17 percent this enrollment season compared with last year, according to data released Thursday by the Centers for Medicare and Medicaid Services.

"Hi everybody, I just wanted to take a moment to remind you that the days are going by quickly here," Whitmer said. "On December 15th, that is the last opportunity to sign up for health care through the Affordable Care Act, so I'm encouraging you to take that time right now and get signed up, 'cause every one of us deserves access to affordable, quality health care."

Open enrollment began Nov. 1 and runs until Dec. 15 in most states. People who do not sign up for an Obamacare plan by the end of open enrollment will not be able to obtain coverage until the fall of 2019, unless they have a so-called qualifying life event such as getting married or having a child.

The last-minute push comes as sign-up rates are down 11 percent this year on HealthCare.gov, the federal health insurance exchange that serves much of the United States.

According to the most recent poll from the Kaiser Family Foundation, only 24 percent of Americans ages 18 to 64 are aware of the current open enrollment deadlines.

Consumers still have three days to sign up, so researchers can't draw any hard conclusions on impacts until the final numbers are in.

Despite weaker enrollment, most policy researchers expect to see a surge in enrollment as states near Saturday's deadline. The CMS said it saw the highest traffic of this open enrollment period on Monday.

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