But Medicaid is a joint federal-state program, with Washington putting up the majority of money and leaving administration to states, as long as they keep within certain guidelines. And for most of the program’s history, the majority of states stuck to the minimum requirements, or relatively close, meaning they limited coverage to certain categories of people, including children, young single mothers, and the elderly.

The Affordable Care Act’s designers sought to turn Medicaid into something much more ambitious: a program for all low-income Americans, so that it was open to any citizen with an income below or just above the poverty line, even if they were working-age men or fell into another demographic category the program had excluded previously.

To put it another way, they were out to transform Medicaid from a narrowly targeted welfare program into part of a universal coverage scheme.

But the interest in ending expansion funding is still there—in no small part because the money is still there—and in recent years especially Republicans have spun their efforts more as an attempt to preserve Medicaid for what they say are the truly vulnerable groups that need it.

One source for this argument is the Paragon Health Institute, one of several think tanks launched by alumni of the first Trump administration, whose researchers have argued that adding all of these working-age, childless adults to Medicaid has put extra financial strains on the program, while overwhelming the doctors and other providers who see Medicaid patients. As a result, these researchers say, the children, pregnant women, seniors, and people with disabilities who had previously depended on the program now have a harder time getting care.