The impending Republican drive to repeal the Affordable Care Act is crystallizing the class contradiction long embedded in the health-care debate.

From the start, President Obama’s health-care reform has faced fierce opposition from working-class whites, the same constituency that anchored Donald Trump’s electoral coalition. But blue-collar whites have been among the law’s principal beneficiaries, particularly in the Rustbelt states that tipped the 2016 race to Trump. The critical question now is whether the practical prospect of losing coverage will dislodge the ideological skepticism about the law that is endemic in white working-class communities.

Since Bill Clinton’s presidency, some Democratic strategists have viewed a pledge to provide universal health care as the party’s best opportunity to refute the widespread view among blue-collar whites that Washington cares less about struggling working families than it cares about the poor (which many of those whites equate mostly with minorities). Yet Obamacare did more to reinforce those perceptions than dissolve them.

In polling by the non-partisan Kaiser Family Foundation, as few as one in eight whites without a college degree have said they believe the law has helped their own families. Far more of those working-class whites have said they believe the law benefits the uninsured and the poor. Most blue-collar whites, in other words, have seen Obamacare less as a universal program, like Social Security or Medicare, that provides a benefit they consider earned, and more like food stamps or welfare that transfers their tax dollars to recipients they tend to consider undeserving. Many college-educated whites have also held that view, though by less emphatic margins.

Blue-collar whites remain the locus of opposition to the law. In the Election Day exit poll, the share of whites without a college degree that said the ACA “goes too far” was nearly double the combined portion that said it didn’t go far enough or was about right. By comparison, non-whites split by more than 2 to 1 in favor of those more positive responses, and college-educated whites divided about evenly. The blue-collar whites who said the law went too far preferred Trump over Hillary Clinton by nearly 13 to 1, according to results from the CNN polling unit.

And yet, for all this skepticism, in practice millions of blue-collar whites have gained coverage under the law, particularly in states critical to the Republican electoral map. Using census data, the Urban Institute recently calculated that from 2010 through 2015, more non-college-educated whites gained coverage than college-educated whites and minorities combined in all five of the key Rustbelt states that flipped from Obama in 2012 to Trump in 2016: Iowa, Ohio, Michigan, Wisconsin, and Pennsylvania. Whites without a college degree also represented a majority of those gaining coverage under the law in core Trump states like Indiana, West Virginia, Kentucky, Arkansas, and Oklahoma.

These states often saw enormous reductions in the number of uninsured working-class whites: about 40 percent in Indiana, Pennsylvania, and Wisconsin; roughly 50 percent in Ohio, Iowa, and Michigan; and 60 percent in West Virginia and Kentucky.

Because minorities represented most of those gaining coverage in many of the biggest states, like California and Texas, they still represented a majority of those obtaining health insurance nationwide, the Urban Institute found. But in all, 6.2 million non-college-educated whites have gained insurance under the law, compared with about 9 million minorities. Obamacare slashed the share of uninsured non-college-educated whites from 20 percent in 2010 to 12 percent in 2015.

That doesn’t mean all of the blue-collar whites covered under the law—or, for that matter, beneficiaries from any other demographic group—are satisfied with it. The principal complaint about the ACA from recipients has been that it costs too much, both in premiums and out-of-pocket costs. Yet the alternatives congressional Republicans have floated seem more likely to compound than resolve those concerns, particularly for blue-collar whites.

The replacement plans Trump and his allies in Congress have suggested could impose greater financial risk from two directions. The most obvious risk is that the replacement proposals won’t provide tax credits for the uninsured as large as the law’s current subsidies; that would drive recipients toward less comprehensive plans that require more out-of-pocket spending, even if the initial premiums are lower.

The more subtle risk is that Republicans will repeal an array of ACA reforms that require insurers to pool risk between the young and old, healthy and sick—such as the law’s limits on how much more they can charge older customers than younger ones. That would mean higher costs for blue-collar whites, generally an older population.

That risk is reinforced by the Republican determination to allow insurers to sell health insurance across state lines. Interstate sale would allow insurers from states with little regulation to offer low-cost, stripped-down plans in states that require comprehensive benefits. If healthier consumers from the comprehensive states flock to those skimpier plans, the families with greater medical needs left behind could face vastly higher costs. “You would be making coverage more affordable for healthier, younger individuals but less affordable for those who are in poorer health and older,” said Edwin Park, vice president for health policy at the Center on Budget and Policy Priorities, a liberal research and analysis group. Even older and sicker people with employer-provided coverage would pay more if Congress repeals the ACA’s reforms limiting out-of-pocket expenses and preventing insurers from imposing annual or lifetime benefit caps.

That may not have been exactly what making America great again meant to the roughly three-fifths of whites older than 45 and two-thirds of blue-collar whites who backed Trump. And that in turn may help explain why congressional Republican leaders are so determined to repeal Obamacare first—and only detail their replacement later.