A remarkable two-track dynamic has developed on the politics of the Affordable Care Act. And it has obvious ramifications for both Democrats and Republicans in the 2020 elections.

It’s this: Even as President Trump and national Republicans remain as zealous as ever about destroying the ACA, the logic of its Medicaid expansion is proving politically irresistible in numerous states — including deep red ones.

The latest red state to move toward expanding Medicaid is Missouri. The state’s governor, Mike Parson, has announced that if a ballot referendum expanding Medicaid passes, he’ll carry out the proposal, even if he personally disagrees with it.

It remains to be seen if that will happen, and this is hardly a full-throated endorsement. But it’s more movement. The group pushing the expansion estimates it would mean health coverage for some 200,000 people, and it has collected around one-fourth of the signatures it needs for the referendum.

Polls suggest the initiative may indeed pass, and notably, Parson faces a Democratic challenger who supports the Medicaid expansion. Indeed, the Medicaid expansion is becoming a winning issue in many parts of the country: This comes right on the heels of Democrats winning control of the Virginia state legislature, and two high-profile gubernatorial contests in Kentucky and Louisiana.

In all of those, the Medicaid expansion was a big driver. Indeed, the pollster for the reelected Democratic governor in Louisiana recently told this blog that it was the single most important issue in the election.

What this really shows is how irresistible the logic of the Medicaid expansion is, even in places that opposed Obamacare with white-hot fury.

“Almost 10 years after the ACA was enacted, the anti-Obamacare symbolism of opposing the law’s Medicaid expansion is fading, and it’s becoming increasingly difficult for red states to stand in the way,” Larry Levitt, executive vice president for health policy at the Kaiser Family Foundation, told me.

“With the federal government paying for 90 percent of the expansion,” Levitt added, “it’s hard for states to make a fiscal argument that it’s not affordable.”

Precisely because GOP lawmakers keep trying to stand in the way of it, the referendum is emerging as a tool for voters to try to force this logic on them. In 2018, referendums passed in three deep-red states — Idaho, Nebraska and Utah — and the expansion has been adopted in all three.

In total, 37 states have now expanded Medicaid — many of them red — while 14 have not. It’s true that the holdouts are some of the big ones — such as Texas, Florida and North Carolina — and this remains a serious impediment to progress.

But still, the expansion continues to march forward, and the politics of it are putting Republicans on the defensive in some of the reddest parts of the country.

And yet, even as this is happening, Trump and Republicans remain fully committed to trying to destroy the ACA. The law is in solid shape, with many millions enrolled all over the country, premiums falling in many places and the Medicaid expansion bringing health coverage to poor and working people in two-thirds of states.

Yet the Health and Human Services secretary amazingly continues to assert that it “doesn’t work,” apparently because this is a requirement in a GOP administration. And an ongoing lawsuit backed by Trump could still gut the law.

The forward march of the Medicaid expansion in red states shows how politically crazy this is. Indeed, we’re seeing lots of previous assumptions about the politics of health care get upended.

For instance, it’s sometimes said the reason Democrats won the House on health care was mainly through vowing to preserve the law’s protections for people with preexisting conditions. It’s also sometimes said that, by relying heavily on more affluent suburban voters as part of their anti-Trump coalition, Democrats may find it harder to enact more progressive change later.

Yet the Medicaid expansion’s continued momentum shows that the part of the law associated with expanding the safety net to lower-income people is also popular — in red territory, and in the suburbs, which drove the Virginia, Kentucky and Louisiana victories.

Indeed, one has to ask whether Medicaid is starting to approach the political durability of two other big welfare-state achievements of the 20th century — Medicare and Social Security.

“Medicaid is often underestimated as a powerful political issue,” Levitt told me, pointing to a recent Kaiser poll, which found that 71 percent of Americans have been covered by Medicaid themselves or had a child covered, or know a close friend or family member who used the program.

“This is a program that has touched a lot of lives,” Levitt added.

Do Trump and Republicans really want to go into the 2020 elections on the wrong side of this issue at best, and having destroyed the ACA at worst? Apparently so.

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