Despite low unemployment rates, positive trends in family income and lower poverty rates, the ranks of Americans without health insurance jumped by nearly 2 million people last year.

What’s going on? Are people going without insurance because they can afford to pay out of pocket when they get sick?

Doubtful. American health care is the most expensive in the world, and paying full sticker price to treat a major illness would break all but the wealthiest families.

Are they dropping coverage because they don’t need it?

Impossible. Everybody needs health care at some point in their lives and no one knows when. For most people, private health insurance is the only way they can be sure they will be able to afford the care they need.

What we are seeing is a direct result of actions by the Trump White House and the Republicans in Congress to dismantle the Affordable Care Act, which extended coverage to nearly 20  million Americans, including 40,000 Mainers.

Republicans have made dismantling Obamacare a priority since the law was passed in 2010. In the Senate in 2017, Susan Collins, Lisa Murkowski and John McCain narrowly prevented their fellow Republicans from gutting the whole program, which would have dumped 22 million people off the insurance rolls. But the party didn’t stop there.

The Trump administration has made it harder to sign up for coverage by cutting the marketing budget and reducing the period in which people can enroll. But according to health care economists, one of the biggest factors was the repeal of the tax penalty for people who don’t buy insurance.

Collins supported the change, pointing out that 80 percent of people who were assessed the penalty earned less than $50,000 a year.  They were being penalized because they couldn’t afford to buy insurance, she said. But as we feared when we encouraged Collins to vote against the deficit-busting tax cut, repeal of the individual mandate is making a bad situation worse.

Since it’s still illegal for insurance companies to deny coverage to people with pre-existing conditions, the Republicans have provided an incentive for younger, healthy people to drop their insurance, knowing that they could resume coverage if they got sick. The goal of Obamacare was to get those people into the insurance pool, spreading the costs more broadly. A smaller pool made up of sicker people will require higher premiums and drive more healthy people out of the system.

Obamacare has always been a less-than-perfect solution to a complex problem. It leaves too many people uninsured and succeeded only in slowing runaway cost increases.

But the problem with the Affordable Care Act has always been that it’s not affordable enough, not that it provides too much care.

Congress should be working on ways to reduce costs while increasing coverage. By what it’s doing now, it’s accomplishing just the opposite.