A REMARKABLE THING just happened in the people’s party. Democrats have chosen a candidate, in the year 2008, who does not have a plan for universal health coverage. Barack Obama caresses the words “universal coverage” almost hourly, but his proposal offers nothing of the kind. The plans of Hillary Clinton, John Edwards and other Democratic hopefuls offered universal coverage.

Most striking, the man who showed such timidity on health care became the hero of ardent progressives. So forgiving was their love of Mr. Big that they virtually abandoned what should have been the Democrats’ most potent promise: medical coverage for all.

This is political opportunity lost. In a new CNN/Opinion Research Corp. poll, 49 percent of registered voters list the economy as their No. 1 issue, with the Iraq war second at 19 percent. Health care comes in a close third at 14 percent.

Make no mistake: A universal health-care system is an economic as well as social imperative — the idea that in a rich country, no one should go without medical care. The lack of one hurts Americans’ ability to compete with foreigners whose governments have controlled total national health-care costs and achieved much better average health outcomes than we have through their rational systems of universal coverage.

So how are voters to compare the health-care proposals of Obama and presumptive Republican candidate John McCain?

McCain proposes tax credits for families to buy their own coverage. This is not the freshest of ideas, though he does call for federal aid to help states cover sick people rejected by private insurers. McCain opposes a mandate requiring everyone to get health insurance.

And so does Obama. He would insist that all children have health coverage, but not adults. As he said during the recent campaign, “Senator Clinton believes the only way to achieve universal health care is to force everybody to purchase it.”

The thing is that a health-care system based on private coverage that doesn’t force everyone to participate is, by definition, not universal. What happens is that the young and healthy don’t bother buying in. (They figure that they can always glom onto a taxpayer-supported program, should they face a medical crisis.)

The inevitable result is that the government programs fill with expensive patients, while the hearty souls — who in any coherent system subsidize their sick neighbors — get to sit on the sidelines. This is a disaster.

The logic of Obama’s argument isn’t great either. His line about Hillary forcing people to buy insurance was followed by this: “And my belief is, the reason that people don’t have it is not because they don’t want it but because they can’t afford it.” Well, if his plan makes health insurance affordable, why can’t everyone afford it?

For the record, McCain also vows to make coverage affordable for all. And although his more free-market approach to health care can’t possibly deliver on this (without spending a lot more than he says he will), the McCain vision stands on a sturdier reality.

The best idea is to enroll all Americans in Medicare. This would be much simpler and administratively cheaper than either the McCain or Obama (or Clinton) plan. As it now does for the elderly, Medicare would pick up most of the hospital and physician bills for everybody. An expanded Medicare would free businesses from the burden of providing medical care to employees and their kin.

Obama’s health-care plan looks like a back-of-the-napkin scribbling by someone who didn’t care all that much but needed something. How curious that out of the smoke and drama of the Democratic race, there emerged a “candidate of change” whose health-care proposal is not universal, much less bold.

Froma Harrop is a member of The Journal’s editorial board and a syndicated columnist.