The final battles of any war often are the bloodiest. They’re waged by the last holdouts, dead-enders desperate to prove to themselves and their dwindling followers that their efforts were not in vain.

The final battle of the war over the Affordable Care Act is being waged today over expanding Medicaid. As the act was originally conceived, Medicaid would provide health care for more than 10 million of the poorest uninsured Americans, most of them childless adults with earnings up to 138 percent of the federal poverty level. (This year, that income ceiling is about $16,000.)

Then the Supreme Court ruled in 2012 that Congress couldn’t impose the expansion on state governments but had to make it voluntary. Republican legislators and governors in 28 states turned the expansion down. A handful later reversed themselves. These include four that, with federal permission, are temporarily trying out novel Medicaid formats.

The refusal of more than half the states to cover so many of their neediest citizens — the number who have fallen into the “coverage gap” is estimated at 5 million — amazes and frustrates health experts. That’s especially so because the federal government covers 100 percent of the cost of expansion through 2016. After that, the federal share will slowly decline to 90 percent in 2020 and beyond.

The holdout states are “willing to sacrifice billions of dollars of injections into their economy in order to punish poor people,” observed Jonathan Gruber, a health economist at MIT who helped design the health insurance reform in Massachusetts on which the ACA was modeled. Speaking in a recent online video chat with health economist Harold Pollack, Gruber added: “It really is just almost awesome in its evilness.”

In many of those states, however, the issue is either dead or the battle is still going on. Last week, for instance, legislators in Maine narrowly failed to override Republican Gov. Paul LePage’s veto of two measures to bring Medicaid to 70,000 of the state’s low-income residents. LePage said he vetoed the expansion “for the sake of the truly needy and Maine taxpayers.”

In Virginia, newly elected Democratic Gov. Terry McAuliffe has fought his Republican Legislature to a draw. He’s determined to implement the expansion; the Legislature seems equally determined to resist it, even if that means a legislative deadlock that results in a state government shutdown. At stake is coverage for 400,000 citizens and budgetary savings of about $600 million through 2022.

The non-expansion states have several qualities in common, aside from their partisan coloration. Of the 20 states with the highest percentages of uninsured citizens 64 and younger, 12 have turned down expansion; non-expansion states also account for 21 of the 35 states with uninsured rates of 15 percent or higher.

Their existing Medicaid programs are typically among the most grudging in the nation. Their median eligibility ceilings are 46 percent of poverty-level income. In Alabama, the stingiest state, parents of dependent children aren’t eligible for Medicaid if they earn more than $3,221 a year. Texas, that great magnet for business, isn’t far behind: Its Medicaid ceiling is $3,737.

What’s most curious about states with Republican leaders ostensibly devoted to fiscal responsibility is that shunning Medicaid expansion makes no budgetary sense, given the huge federal financial commitment and the potential for reducing other state costs, including the public cost of treating uninsured patients.

Adding to the perplexity are the signs that citizens in the holdout states are plainly eager to take advantage of Medicaid. Michigan, one of the few states with a GOP governor and Legislature that agreed to expand Medicaid, signed up nearly 159,000 residents — almost one-third of all those eligible — in the first four weeks of enrollment. But they moved too late to take enrollments before April 1.

Too many Republican officeholders appear to be intent on denying health care to their neediest citizens. As the Kaiser Family Foundation has documented, before the ACA, states invariably sought waivers to expand Medicaid to populations not normally covered by the program; now their goal is to expand it as grudgingly as possible.

What we are witnessing are the death throes of the anti-Obamacare crowd. Expanded access to health coverage is here to stay. The GOP’s resistance to expanding Medicaid has merely turned 5 million Americans into refugees from ideological warfare, awaiting the moment when peace offers them a chance at better health.

Michael Hiltzik is a columnist for the Los Angeles Times. Email at mhiltzik@latimes.com. This column was distributed by MCT Information Services.