If the GOP repeals ObamaCare, Americans will die. Lots of them.

Nonetheless, Republicans are laying the groundwork to repeal the Affordable Care Act, President Obama's signature health reform law, which has delivered health insurance to well over 20 million people. So let's speak plainly: You simply cannot scrap this law without negatively affecting the health of far too many of these 20 million people. It is indisputable that killing ObamaCare will actually kill people. (Don't believe Republican claims that they'll replace ObamaCare with something terrific. They won't.)

None of this is to say that ObamaCare is awesome. It isn't. The insurance provided on the ObamaCare exchanges is pretty lousy for many people. Many of the exchanges have not attracted enough young people, the deductibles and premiums are too high, the subsidies are too stingy, the provider networks are too narrow, and it seems to be getting worse over time. The basic structure of the exchanges — a jerry-rigged device "trying to use markets to distribute something that, at the end of the day, we don’t want distributed according to market forces," as James Kwak writes — is patently rather silly. Yet as Jordan Weissmann argues, neither are the exchanges close to actual collapse. Millions of people are getting relatively decent insurance, and millions more have coverage that's at least better than nothing. More importantly, the majority of the coverage increase under ObamaCare has come from Medicaid expansion. This part of the law is an unqualified success, at least in the states where the expansion took hold.

The bottom line is clear: ObamaCare is imperfect, but it is far better than nothing.

So what happens if Republicans repeal ObamaCare and replace it with nothing? What toll of misery and death shall be collected?

Sanders' number comes from a study of Massachusetts' health-care reform, passed when Mitt Romney was governor. It found a decrease in the death rate of 8.2 per 100,000 adults, and Sanders (cribbing from ThinkProgress) applied that rate to an Urban Institute estimate of 30 million people losing their insurance under a clean ObamaCare repeal. (Washington Post fact checker Glenn Kessler tut-tuts that Sanders picked a high estimate, improperly generalized from Massachusetts to the rest of the country, didn't cite other somewhat lower estimates, and failed to consider the idea that removing health insurance might not have a mirror-image effect from handing it out. As far as quibbles go, they're weak at best.)

Sanders might actually be undershooting the true number. Indeed, starting with the Massachusetts number could easily create a lowball estimate, as it is a relatively healthy state. And the Congressional Budget Office released an analysis Tuesday of a 2015 Republican repeal plan with a higher estimate of people losing their insurance: 18 million in the first year, and 32 million by 2026.

But let's not quibble over the exact math. The fundamental truths are plain as day. Research has consistently concluded that lack of insurance kills people. Here's a list of six studies spanning two decades, all finding tens of thousands of excess deaths among the uninsured. The most recent, a Harvard study from 2009, found nearly 45,000 people dead yearly due to lack of insurance, and an increased risk of death among the uninsured of 40 percent. Lead author Dr. Andrew Wilper provided the bleeding obvious reason why: "We doctors have many new ways to prevent deaths from hypertension, diabetes, and heart disease — but only if patients can get into our offices and afford their medications." What's more, before ObamaCare, the uninsurance rate had been trending up for years, suggesting that the post-repeal rate will be even higher than in 2010.

The exact number of onrushing deaths pales in comparison with the ironclad certainty that it will be in the tens of thousands. And for every death, there will be dozens of people enduring illness they can't afford to treat, or being bankrupted by emergency care they cannot afford.

The GOP has had more than six years to figure out its preferred ObamaCare replacement policy. Days before Donald Trump is set to assume the presidency, they still have nothing. The reason is obvious — there is no more conservative replacement that can possibly provide comparable coverage, and even if there were, it would interfere with the GOP's goal of huge tax cuts for the rich. Philip Klein, a conservative health policy analyst, suggests the obvious escape hatch: Republicans should just admit that "we don't believe that it is the job of the federal government to guarantee that everybody has health insurance."

That austere libertarian purity has at least the virtue of honesty and consistency with conservative principles. Taken to its logical conclusion, it would mean abolishing not just ObamaCare, but also Medicare, Medicaid, SCHIP, and the Veteran's Administration. It would mean health care allocated by price — the rich get good care, the middle class get decent care (and routinely bankrupted by serious illness), and the poor get nothing.

But one does not need a graduate degree in health policy to understand the root of this issue. ObamaCare, for all its flaws, has dramatically expanded access to health care. When people cannot get care, they occasionally die of treatable illness. An ObamaCare repeal with nothing good to replace it? That would be tantamount to mass murder.