Like too much else in Washington, the slow-motion collapse of Obamacare was an eminently avoidable crisis. The question, now that it is happening, is whether President Donald Trump and Congress want to work together to contain it.

Related: 1 in 4 Americans skip medical attention because of cost

With Anthem Inc.'s alarming decision to quit Ohio's health-insurance marketplace, 18 more counties can now be added to the territory where people who qualify for federal subsidies will have no insurance plans to buy next year. Trump has actively sought to destabilize the law — by repeatedly threatening to withhold federal payments owed to health insurers, making it easier for people to dodge the tax penalty for not having insurance and, with Congress, threatening to replace the law with a system that would separate millions of Americans from health insurance.