As this week’s Democratic debates made clear, the party is divided on how to improve health care for Americans. Bernie Sanders, Elizabeth Warren and others are for a single-payer Medicare for All system. Joe Biden, Pete Buttigieg, Amy Klobuchar and others want an incremental approach building on the Affordable Care Act.

But candidates who are battling over plans like Medicare for All (Mr. Sanders) versus Medicare for All Who Want It (Pete Buttigieg) versus Medicare for America (Beto O’Rourke) versus BetterCare (John Delaney) — and many others — are having the wrong debate. Instead, they should be competing to find the best ways to tackle affordability — an issue they can all agree on and President Trump has done nothing about.

Democrats are deeply concerned about achieving universal coverage. The simple way to do that is not through a single-payer Medicare for All plan, which faces daunting political opposition. Instead, they can get coverage for most of the remaining 28 million or so Americans with auto-enrollment. Changing some existing policies, like harmonizing the income eligibility standards for Medicaid and the insurance exchanges, would enable the government agencies, hospitals, insurers and other organizations to enroll people in health insurance automatically when they show up for care or other benefits like food stamps.

For the other 295 million Americans who have some form of health insurance, the problem is high costs. Even with health insurance, high premiums, deductibles and co-pays, surprise hospital bills and exorbitant drug prices inhibit people from accessing care and taking their medications, threaten to drain their savings, or even force Americans into bankruptcy. Democrats need a plan to deal with this problem.