Alberto Abin walks out of the UniVista Insurance company office after shopping for a health plan on December 15, 2015 in Miami, Florida. (Photo by Joe Raedle/Getty Images)

If Republicans repeal the Affordable Care Act, President Obama's health reform law, they will have achieved something rare. Even when conservative policymakers have complete control of government — as Republicans will in Washington once Donald Trump assumes the presidency — they have generally failed to eliminate major social programs after those programs have been established.

The programs' popularity with beneficiaries is always an obstacle, one that Republicans will have to contend with as they dismantle Obama's reforms.

“Social programs don’t tend to disappear, precisely because people don’t like to lose benefits once they’ve gotten them,” said Julia Lynch, a political scientist at the University of Pennsylvania. “It just doesn’t happen.”

All the same, there are past instances of successful conservative reforms that could guide GOP lawmakers as they work out how they will fulfill their pledge to replace the law with a better system. In the United States and abroad, conservative policymakers have made their policies more palatable by delaying the most punitive changes for many years, compensating those who are directly affected or limiting benefits for the middle class to protect the poor.

These instances are also cautionary examples for defenders of the law who hope that Republicans will ultimately balk at repealing it. Those optimists apparently include Obama himself, who told Vox in an interview last week that he thinks his reforms might endure.

The best precedent for undoing Obama's policies is probably the repeal of the old U.S. welfare system in 1996. President Clinton and Republicans in Congress replaced that system with a new one, eliminating poor Americans' entitlement to financial help from the government based on their incomes.

The new system generally requires that recipients work, volunteer or participate in vocational training to get help. Over time, these changes made the program much less generous, but there was no immediate crisis. The reform gave states ample resources to help recipients find work. Economic conditions were good, and many who left the rolls could obtain employment.

By 2012, though, average monthly benefits had lost over a quarter of their value to inflation, according to the nonpartisan Congressional Budget Office. Meanwhile, the share of poor families receiving those payments declined by roughly 60 percent, as it has become increasingly difficult for those in need to qualify for help.

Like Clinton, British Prime Minister Margaret Thatcher implemented reductions in social programs that took effect gradually. “Nobody wants necessarily someone out on the street right away,” said Jane Gingrich, a political scientist at the University of Oxford. “It just didn't happen all at once in one big repeal.”

When she assumed office in 1979, gross unemployment benefits replaced on average 24 percent of a British worker's wages, according to the Organization for Economic Cooperation and Development. Twenty years later, that figure had declined by about a third, to 17 percent. (The data does not account for taxes or other benefits, such as family and housing assistance.)

These episodes might explain the instinct behind the strategy, proposed by some Republicans, of repealing the health-care law and then delaying its replacement for a few years. Whether a delay is feasible is unclear, though. Conservative economists and experts have warned that repealing essential provisions of the Affordable Care Act without putting a new system in place could cause chaos in the individual market for insurance.

Thatcher's housing policies demonstrate another potential strategy for conservative policymakers. She privatized swaths of publicly owned housing by encouraging tenants to buy their homes.

Sales were voluntary for tenants, who could buy their houses from the government at prices well below their actual value. She combined a free-market reform with a lucrative subsidy for the program's current beneficiaries that fostered support and stymied opposition.

Since her program began in 1980, 1.8 million units have been sold, according to government data. Those sales substantially reduced the public sector's involvement in a crucial sector of the economy and in the lives of ordinary British people.

“To anybody who says, 'Oh, the ACA can’t be repealed because too many people benefit from it,' I would say look at public housing under Thatcher,” said Lynch of the University of Pennsylvania. Detractors of Thatcher's policy say that in the long term, bargain-basement sales of publicly owned homes left British housing officials without enough properties to provide an affordable place to live for everyone who needed one.

It seems unlikely that Republicans in Congress could take a similar approach this year.

Under Thatcher, if you liked your home, you could keep it. There is no guarantee that if Republicans make major changes to how health insurance is regulated, those who currently benefit from the Affordable Care Act will be able to maintain the same insurance they have now. Those policies might become unprofitable for insurance companies, which could stop offering them.

A final option for Republicans would be to try to focus on protecting the poorest beneficiaries of the current system, so that the burden of repeal falls on those who are better able to manage the costs. Reducing benefits overall, but less so for the poor, has been a feature of many European reforms of social policy.

Former German chancellor Gerhard Schröder's reforms to unemployment insurance are one example. Previously, those who were unemployed for a long period could receive a payment based on their prior earnings. Beginning in 2005, they could receive benefits only at a flat rate and only if they were poor enough to qualify.

While the new program was less generous for all workers, it was especially hard on more affluent Germans who could previously receive a substantial share of their prior salary after becoming unemployed.

Swedish policymakers have made similar changes, reducing the level of benefits overall while making them more progressive fiscally. They reduced the maximum benefit for unemployed workers beginning in 2007, effectively limiting the amount that people who had more income before they became unemployed could collect from the system.

“The higher earners are less vested in the system,” Oxford's Gingrich said.

Republicans could follow this template by preserving Obama's expansions of Medicaid, which help the poorest Americans buy insurance. A number of GOP governors have supported this policy, including Vice President-elect Mike Pence, who worked with the Obama administration to expand Medicaid in Indiana.

In any case, it seems likely that Republicans will seek some kind of compromise that allows them to preserve the law's more popular provisions.

“Parts of it will be taken away. Parts of it will be left in place, and other parts will be changed a little bit,” said Lane Kenworthy, a sociologist at the University of California at San Diego. “It's not going to be a true repeal. It's not like everything goes off the books.”

Kenworthy argues that over the long term, U.S. welfare and social policy will become more generous as liberal policymakers expand old programs and create new ones and their conservative opponents fail to wholly undo them. Eventually, he said, he is confident that the country will offer its citizens universal health care — despite the likelihood that Republicans will retrench Obama's reforms.

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