A big U.S. social insurance program is enacted into law – only to face delays and fierce controversies. Regulations are imposed on businesses and taxes collected well before citizens get sizable benefits. Right-wingers fight for repeal or evisceration, and many on the left are also disgruntled. Outright failure remains possible for years after enactment.

Obamacare? No, we’re talking about the early life of the program called Social Security, now hugely popular and regarded as virtually untouchable politically.

Social Security was enacted in 1935, but no one got a check until the first small benefit was issued in 1940. Scheduled revenues vital to the program’s viability were repeatedly delayed, and conservatives and leftists tried to scuttle it altogether. Not until the mid-1950s did Eisenhower-era Republicans finally accept Social Security; and it took until the early 1970s for generous benefits to make it widely popular.

Compared to this long story, Affordable Care is advancing at warp speed. Sure, Republicans are still fighting a rear-guard war for “repeal.” And an impatient media blows every tiny glitch into Armageddon. Political reporters have a vested interest in the notion that Obamacare is still up for grabs if Republicans take control of the Senate next November.

But let’s look at the unfolding realities, starting with the health insurance facts.

More 10 million Americans are already newly signed up under Obamacare, more than a quarter of those previously uninsured. A few years ago, the percentage uninsured was steadily rising, but now Gallup and other trackers show it markedly declining. And that does not count the millions who now have better-quality and more secure health insurance that cannot be cancelled.

Younger people have been slow to sign up on the exchange marketplaces, but now many are. In addition, some 2.6 million have gained coverage on their parents’ insurance until age 26. These mostly middle-class young adults and their families will want continued coverage after that.

Insurance companies, health care providers, and many state governments have worked for years to accommodate new regulations and subsidies. Far along toward new ways of doing business, they don’t want fundamental upheavals.

Even during the most difficult days of the national rollout, one GOP-led state after another signed on to the expansion of Medicaid funded through Affordable Care, taking the total from 23 to 27 states in recent months, with more to sign on soon. The huge federal subsidies are just too good to refuse; and the Obama administration is allowing Republican states to modify the program along market-oriented lines.

As for the politics, pundits who say health reform still favors refuseniks are dead wrong.

True, divided public assessments of the law have hardly moved since 2010. (Democratic disgruntlement briefly spiked in late 2013, but now Democrats are becoming more enthusiastic than ever.) Partisan divergences remain, yet over recent months the proportion of all Americans supporting repeal has declined sharply. Most people now say keep the law and fix it. Even more of all partisan persuasions correctly believe that the law is beyond repeal.

GOP strategists may think “repeal Obamacare” is a good battle cry for a mid-term election in which Democratic turnout usually falls. But so what? Let’s assume Republicans take the Senate majority. Repeal and evisceration will still be impossible with Barack Obama in the White House, and the day after the November 2014 election, the 2016 elections will loom as dangerous for Republicans. Democratic voters will turn out in 2016; and the Senate seats at issue 2016 will include many with GOP Senators facing reelection in blue states. Given these prospects, we will not likely see majority Senate votes to repeal or gut Obamacare – in effect, to roll back benefits large chunks of voters already enjoy. We will see evasion and refusal to go that route from endangered 2016 GOP incumbents like Senators Mark Kirk of Illinois, Pat Toomey of Pennsylvania, Ron Johnson of Wisconsin, Rob Portman of Ohio, and even John McCain of Arizona.

Voter support for reform and its likely evolution is also widely misunderstood. Top-line popularity may change very little, but about a fourth of those with reservations want a more generous government program like Medicare for All. And people of all partisan leanings tell pollsters they overwhelmingly approve core Obamacare provisions – including rules keeping insurance companies from avoiding or dumping people with health problems; subsidies to help families and businesses afford private plans; expansions of Medicaid to insure more low-income; and new benefits for women, youth, and Medicare recipients. Before 2014, many Americans did not know such specifics were included in the law, but by now millions do know – and the word is spreading to their kinfolk, neighbors, and co-workers.

In politics, losses always worry people more than abstract future gains entice them. Now, every vote to repeal or eviscerate Obamacare risks offending millions – and the potential to arouse pushback will only grow. This story isn’t like Social Security, where most potential beneficiaries saw few gains for two decades. Affordable Care is already a massive presence in U.S. health care. It cannot be rolled back and those who keep championing that Lost Cause will do so at rising political peril.

Theda Skocpol is the Victor S. Thomas Professor of Government and Sociology at Harvard University, and the director of the Scholars Strategy Network. With Lawrence R. Jacobs, she is the author of Health Reform and American Politics: What Everyone Needs to Know (Oxford University Press).