In their final debate before they face Democratic primary voters, Hillary Clinton and Bernie Sanders traded sharp jabs on health care. Pundits focused on how the barbs would affect the horse race, whether Democrats should be bold and idealistic (Sanders) or shrewd and practical (Clinton), and how Sanders’ “Medicare for All” scheme would raise taxes by a cool $1.4 trillion. (Per. Year.) Almost no one noticed the obvious: the Clinton-Sanders spat shows that not even Democrats like the Affordable Care Act, and that the law remains very much in danger of repeal.

Major insurer UnitedHealth, which caused a stir in the fall by saying it might leave ObamaCare, lost $720 million from the individual health insurance market last year. UnitedHealth said in its financial report released Tuesday that the $720 million comes from losses “related to the individual exchange-compliant insurance business.” About $245 million of that money was for “advance recognition of losses” in 2016 in the individual marketplace.

Judicial Watch today released over 1,000 pages of new documents that show federal health care officials knew that the Obamacare website, when it launched in 2013, did not have the required “authorization to operate” from agency information security officials. These documents, obtained from the U.S. Department of Health and Human Services, come in two productions of records: a 143-page production and an 886-page production. The email records reveal that HHS officials had significant concerns about the security of the Healthcare.gov site leading up to its October 1, 2013, launch.

The decision states face of whether to expand Medicaid to non-disabled, working-age, childless adults—the Affordable Care Act primary expansion population—involves tradeoffs. These tradeoffs include higher taxes, reduced spending on items like education, transportation, or infrastructure, or reduced spending on other Medicaid populations such as the disabled, children, or the elderly. The ACA funding formula allows states to pass a much greater share of the costs of covering non-disabled childless adults to federal taxpayers, but the tradeoffs still exist.

On Sunday, January 17—hours before the Democratic presidential debate on NBC—Vermont Senator Bernie Sanders released details of his proposal to replace the entire U.S. health care system with a universal, government-run, single-payer one. In Sanders’ eight-page campaign white paper, entitled “Medicare for All,” the self-described “democratic socialist” outlines his plan’s core principles.

Warren Gunnels, Sanders’ policy director, retained Gerald Friedman, an economist at the University of Massachusetts at Amherst, to come up with a fiscal score of the Sanders plan. Friedman estimates that the plan would require $13.8 trillion in new government spending in the decade spanning 2017 through 2016. Avik Roy of the Manhattan Institute outlines why that estimate is far too low.

In November, UnitedHealth abruptly reversed its previously sunny take on ObamaCare and said that the company would have to pull out of the government-run exchanges if market conditions didn’t improve.

UnitedHealth’s bombshell raised the specter, once thought safely in the grave, of the “adverse selection death spiral,” the phenomenon where sick people are more likely to buy insurance, which raises the average expenditure, which means higher premiums, which makes insurance a worse deal for the healthiest members of your insurance pool, which means they drop out, which means your pool is even sicker and average expenditure goes up even more … and there goes the insurance market.