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Despite the rise of the Tea Party and unified Republican control of government, one decidedly anti-free-market idea appears ascendant: single-payer health care.

And it’s no wonder, given that a record-high share of the population receives government-provided health insurance. As a country, we’ve long since acquiesced to the idea that Uncle Sam should give insurance to the elderly, veterans, people with disabilities, poor adults, poor kids, pregnant women and the lower middle class.

Many Americans are asking: Why not the rest of us, too?

A recent survey from the Economist/YouGov found that a majority of Americans support “expanding Medicare to provide health insurance to every American.” Similarly, a poll from Morning Consult/Politico showed that a plurality of voters support “a single-payer health care system, where all Americans would get their health insurance from one government plan.”

Divining the longer-term trend in attitudes toward this idea is difficult, as the way survey questions on the topic are asked has changed over time. Views of a health care system in which all Americans get their insurance from the government single payer vary a lot depending on how you frame the question. Calling it “Medicare for all,” for example, generally elicits much stronger approval, while emphasizing the word “government” tends to depress support.

But at the very least, some survey questions that have remained consistent in recent years show support has been rising back up for the broader idea that the federal government bears responsibility for making sure all Americans have health care coverage.

Since 1987, the share of Americans who receive some sort of public insurance has roughly doubled, to about 4 in 10 as of 2015. That’s not even counting the people who receive subsidies to buy private insurance on the Affordable Care Act exchanges.

The increase in the share of Americans on government insurance is partly due to demographics (baby boomers aging into Medicare) and partly due to deliberate policy changes growing the pool of Americans eligible for government insurance (such as the creation of the Children’s Health Insurance Program and Obamacare’s Medicaid expansion).

Expansions of government coverage have been cheered on by many liberals, but they have also bred suspicion and jealousy.

In both the recent YouGov and Morning Consult polls, the age group most opposed to single payer was the only one that basically already has it: those 65 and up. In other words, single payer for me but not for thee.

That’s not because older Americans hate their experience with Medicare and wouldn’t wish something similar upon their worst enemy. To the contrary, those on Medicare are more satisfied with how the health care system works for them than people on private insurance are, according to Gallup survey data.

Rather, seniors are probably worried that expanding government coverage to more Americans could put their own generous benefits at risk.

Many of those outside the growing pool of public-insurance beneficiaries, on the other hand, have become resentful of the fact that everyone else seems to be getting a big fat government handout. Or so they perceive.

Many of the stories in the booming “blue-state reporter ventures into Trump country” genre have featured Trump supporters with deep hostility toward Obamacare, among other government programs. Some of these Trump supporters are, perhaps puzzlingly, themselves Obamacare beneficiaries, receiving government subsidies for private insurance on the individual exchanges. But often what these Trump voters say they want is not a return to pre-Obamacare days; rather, they want in on the great insurance deal that they think their lazy, less-deserving neighbors are getting.

In fact, that recent YouGov poll found that 40 percent of Trump voters support expanding Medicare to all Americans. Among Republicans overall, the share rises to 46 percent.

Among Republican politicians, needless to say, attitudes are somewhat different.

Expanding public health coverage to more people costs a lot of money, which doesn’t exactly jibe with their tax-cutting agenda. House Speaker Paul Ryan and his congressional compatriots seem to further believe — despite all evidence to the contrary — that the private sector is on the verge of some innovation that will magically reduce health care costs and give all Americans the coverage and care they yearn for.

But it’s probably not fair to paint Republicans as the only roadblock here. Even Democrats don’t have the stomach for the battle required to replace our jury-rigged, mostly employer-sponsored insurance system with single payer. Which is understandable — while I also favor universal health-insurance coverage, I’m skeptical it will be achieved through single payer, given both the state of our political process and Americans’ cultural allergy to tax hikes.

Even so, somewhere out there, Bernie Sanders is smiling.

E-mail Catherine Rampell at crampell@washpost.com. Follow her on Twitter: @crampell

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