House Republicans have taken direct aim at Medicaid with their American Health Care Act, which is up for a vote in the House on Thursday. They hate social insurance, and they especially hate any program that benefits the poor — not to mention the fact that programs that include the upper class, like Medicare and Social Security, are more politically risky to attack. So they're trying to slowly strangle Medicaid to death with the same "reform" plan they used on traditional welfare in 1996.

But Medicaid might have an unlikely savior: ultra-conservative House Republicans. They are enraged that TrumpCare doesn't cut enough, and so are thus far promising to vote against the policy. It might just stop TrumpCare from passing the House.

It's not widely known that Medicaid is the largest single insurer in the United States, with nearly 70 million people covered. It's a program for poor and near-poor people, and as such tends to be chronically underfunded and under-noticed — but there are a slew of such people in this grotesquely unequal country.

As my colleague Jeff Spross explains, the original iteration of TrumpCare would have first rolled back ObamaCare's expansion of Medicaid, then changed it from a defined-benefit to a defined-contribution program. That contribution would be indexed to medical inflation — but because the Medicaid population is sicker than average, its costs tend to rise faster than average, thus implying the bill would actually feature large and growing cuts when compared to current law. That adds up to $370 billion in costs shifted to the states over 10 years, which are virtually certain to end up being mostly cuts. And because Medicaid is already far and away the cheapest health insurance in the country, cuts are virtually certain to mean people being kicked off the program.

That wasn't enough for the so-called "Freedom Caucus" of ultra-conservative House Republicans, so Ryan offered them some more goodies, in the form of yet more savage punishment of poor people. An amendment would make it harder to enroll in Medicaid, allow work requirements and drug testing of enrollees, and allow states to take the federal contribution in the form of a block grant.

That finally recapitulates the basic formula of welfare reform: Block grant the money, cap the growth of spending, and add a ton of hurdles to enrollment to shed as many people from the rolls as possible. Then add some reverse-engineered rationalization about how poor people are all lazy drug addicts anyway who don't deserve insurance. (Making it an egregious double standard adds an extra frisson of Christian compassion — you never hear conservatives propose a drug test to claim rich people welfare like the mortgage interest deduction.)

Eventually, the program will be a cored-out shell of its former self. That's why TrumpCare is estimated to be worse than a clean repeal of ObamaCare in terms of the uninsured population.

But even that level of Cormac McCarthy-esque horror is apparently not enough for the ultras, who are still promising to vote against the bill because it's not cruel enough. President Trump has been whipping for the bill as well, all to no avail:

This is exactly what saved Social Security and Medicare during the negotiations over the debt ceiling in 2011. President Obama was ready to throw grandma into the North Sea so he could get the ego boost of a bipartisan Grand Bargain — but he couldn't stomach it without at least a few tax increases, and the ultras refused to accept a single nickel of additional taxation. Thus was grandma saved to bake cookies for another day.

Now, it's certainly possible the ultras are bluffing, and will eventually vote for the bill (where it will run into bigger problems in the Senate). But they are also notoriously terrible at vote-counting. It's anybody's guess what will happen.

It's also worth noting that Medicaid — while a godsend for millions — has its share of problems. But virtually all of them are caused by precisely the sort of policy-design elements Republicans are advocating be strengthened. It's already too miserly, it's too dispersed among the states, and it's got too many janky public-private elements. So if ultra-conservative intransigence saves Medicaid on Thursday, then future reform efforts should go in the opposite direction: Fully federalize the program, ease eligibility requirements, and combine it with Medicare as a first quick step toward a full single-payer system.