Health care is typically one of the top three voter concerns. In the 2018 midterm elections—one year after Republicans tried and failed to repeal the Affordable Care Act—health care ranked as the single most important issue for voters, helping Democrats regain control of the House.

If health care is as important to voters in 2020, it could easily put Democrat Joe Biden into the White House in 2021. New polling by the nonprofit Commonwealth Fund finds that voters in 10 swing states likely to determine the outcome of the presidential race strongly favor Biden over Trump on three health care issues they identify as most important.

Researchers asked voters in Arizona, Florida, Georgia, Michigan, Minnesota, North Carolina, Ohio, Pennsylvania, Texas and Wisconsin which candidate they thought would most effectively handle the COVID-19 pandemic, protect patients with pre-existing conditions and lower health care costs. They also did a national survey on the same questions. In the battleground states, 4,220 likely voters responded, while 1,435 likely voters responded in the national survey.

On handling COVID-19, respondents in 9 of 10 swing states favor Biden, by margins ranging from 51%-44% in Texas, to 60%-35% in Georgia. Only in Ohio did respondents favor Trump over Biden, by 48%-45%. (In each state some respondents said they weren’t sure, ranging from 4% to 10%).

Likely voters in every swing state think Biden would be more effective at protecting people with pre-existing conditions. The lowest marks for Biden come in Texas, where respondents still go with Biden by 51%-41%. Biden’s biggest margin is in Georgia, where likely voters trust him over Trump by 63%-30%.

On lowering health care costs, Biden dominates again, gaining the edge in all 10 swing states. His smallest margin is in Wisconsin, where he beats Trump 50%-38%. His largest margin, once again, is in Georgia, where he leads Trump 59%-35%.

The Supreme Court factor

These findings and others ought to worry the Trump campaign. The Commonwealth survey was almost fully completed before the Sept. 18 death of Supreme Court Justice Ruth Bader Ginsburg, which has direct implications for the Affordable Care Act. The court will hear a case on Nov. 10 arguing that the entire ACA is unconstitutional and should be struck down. Ginsburg was one of four justices considered a reliable vote in defense of the ACA. A new Trump appointee could flip the court against the ACA and endanger the whole law. The court is likely to rule on the new case by next June.

Biden has already begun campaigning on his defense of the ACA, and Trump’s hostility toward it. The Trump administration is a party in the Supreme Court case, siding with the plaintiffs trying to kill the law. The ACA banned the old practice of insurance companies charging more for people with preexisting conditions, or denying them coverage altogether. That would once again be allowed if the court kills the ACA. Trump says he’ll protect people with preexisting conditions some other way, but he hasn’t yet said how, even though he’s been promising a health care plan for much of 2020. Biden could gain further traction if he convinces voters Trump’s third Supreme Court justice could jeopardize their own health care.