Friday is the deadline for 2018 enrollment on the federal Obamacare exchange. States which run their own exchanges, like California, are keeping the enrollment period open longer (the end of January in California’s case). But the enrollment numbers are clearly shaping up to be a downturn from last year and Republicans and Democrats are already casting blame. Politico reports:

“There’s a clear relationship between increasing premiums and decreasing enrollment,” said Sen. Bill Cassidy (R-La.), co-sponsor of a GOP plan to replace the Obamacare in part with block grants to states. “We’re losing people who don’t get subsidies. That’s the reason we’ve got to do something about it.”…

“The reality is the Trump administration is constantly doing somersaults to try to find ways to dissuade people from enrolling,” said Senate Finance Committee ranking Democrat Ron Wyden of Oregon, who on Tuesday joined his counterpart on the Senate HELP Committee, Patty Murray, in calling on the administration to extend the enrollment period from Friday until Jan. 31…

As of Dec. 2, just over 3.6 million Americans had signed up for coverage on the federal exchange HealthCare.gov, and more than 2 million enrolled through state-based marketplaces. That’s about 15 percent ahead of last year’s pace, according to independent analyst Charles Gaba, who runs the website acasignups.net.

However, Gaba projects that final 2018 enrollment will likely top off around 10 million nationwide — roughly 20 percent lower than both 2016 and 2017, when sign-ups topped 12 million.

Gaba is a supporter of the law but his estimates have been pretty accurate over the past several years. You can check his math here. He’s predicting around 7.5 million enrollees on the federal exchange and we could have those numbers next week. Obviously, the final numbers for the independent state exchanges will take longer since they don’t close until next month.

And don’t forget that every year we’ve done this there is a drop-off, between those who select a plan and those who actually pay their first premium, of 10-12 percent. So if the final tally is 10 million nationwide, that would likely drop to 9 million or less within a month or so.

None of this will have much impact on the people getting subsidies, which are the vast majority of people buying on the exchanges. Where it will matter is when insurers start to think about whether to stick around for 2019.