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Guess who's on the hook in one of the largest lawsuits ever? You. More than 100 health insurance companies are suing you and the rest of America's taxpayers. Insurers want you to bail them out for money they lost trying to sell Obamacare plans. The losses could amount to a whopping $15 billion. A ruling from the Court of Appeals for the Federal Circuit is expected any day.

It's a brazen money grab. In 2010, powerful insurance industry officials worked hand in glove with Democrats to enact the Affordable Care Act, a scheme compelling everyone to buy their product. It doesn't get any sweeter, a law making your product mandatory.

But insurers are seeking even more. They claim their cozy deal also insulated them from losing money during the first three years they tried to sell Obamacare plans. Maybe that's what Obama administration officials whispered to health insurers. But the actual wording of the ACA didn't commit even a single dollar of taxpayers' money to offset losses. And twice since then Congress has passed additional laws clarifying that taxpayers will not be compensating insurers who lose money on Obamacare.

Undeterred, the insurers are now trying to convince federal judges to award them what Congress clearly denied. Insurers argue promises made by Obama administration health officials amounted to an "implied contract." Insurers were led down the garden path. Then again, so was the public.

Remember President Obama telling us the average family will save $2,500 a year? Consumers whose premiums have more than doubled since that promise was made aren't getting a day in court to collect. And neither should insurance companies.

Back in 2010, insurers worried that selling health plans to consumers without knowing their health status would be a crapshoot. Some companies would end up with healthy customers and make profits, while other companies might attract more sick enrollees and lose money paying exorbitant medical bills. To avoid that outcome, the ACA set up a risk-adjustment system under which insurers that were profitable selling Obamacare would surrender a fraction of their yearly gains to the Department of Health and Human Services, which in turn would hand it over to insurers who had lost money.

From the beginning, the risk-adjustment system was a flop because virtually all insurers were losing money on Obamacare. The plans were too costly to attract young, healthy buyers. The Obama administration wanted to use taxpayer money to offset the insurers' losses. But Congress, by then under Republican control, acted quickly to prevent it, passing laws in 2014 and again in 2015 to bar it.

At that point, some insurers like Aetna and UnitedHealthCare saw the writing on the wall and pulled out of nearly all Obamacare markets. But other insurers were coaxed by Obama administration officials who assured them they'd be made whole eventually. Anything -- including sweet talk -- to prop up Obamacare.

The Obama administration is at fault here. The U.S. Constitution says the president can't spend what Congress doesn't appropriate. Congress has exclusive "power of the purse" to protect the public's money.

Weighing in on the lawsuit, the House of Representatives says, "Congress has repeatedly legislated to prohibit" giving taxpayer money to insurers to offset their losses.

Quoting the Constitution's chief architect, James Madison, the House calls the power of the purse "the most complete and effectual weapon" that the Constitution provides against profligate spending. Obama administration officials blatantly disregarded that fundamental principle.

Not surprising. In another case, the Obama administration actually paid out money to insurers, reimbursing them for discounts offered to low-income customers, despite Congress's refusal to approve the spending. In that case, the House sued, and the Obama administration lost in court. A federal judge ruled the payments illegal.

That's what should happen again. Otherwise, future presidents will be free to turn taxpayers into ATMs paying for pet projects without congressional approval. And the Constitution will be meaningless.