Now, about those specifics: The HELP plan achieves near-universal coverage through a combination of regulation and subsidies. Insurance companies would be required to offer the same coverage to everyone, regardless of medical history; on the other side, everyone except the poor and near-poor would be obliged to buy insurance, with the aid of subsidies that would limit premiums as a share of income.

Employers would also have to chip in, with all firms employing more than 25 people required to offer their workers insurance or pay a penalty. By the way, the absence of such an “employer mandate” was the big problem with the earlier, incomplete version of the plan.

And those who prefer not to buy insurance from the private sector would be able to choose a public plan instead. This would, among other things, bring some real competition to the health insurance market, which is currently a collection of local monopolies and cartels.

The budget office says that all this would cost $597 billion over the next decade. But that doesn’t include the cost of insuring the poor and near-poor, whom HELP suggests covering via an expansion of Medicaid (which is outside the committee’s jurisdiction). Add in the cost of this expansion, and we’re probably looking at between $1 trillion and $1.3 trillion.

There are a number of ways to look at this number, but maybe the best is to point out that it’s less than 4 percent of the $33 trillion the U.S. government predicts we’ll spend on health care over the next decade. And that in turn means that much of the expense can be offset with straightforward cost-saving measures, like ending Medicare overpayments to private health insurers and reining in spending on medical procedures with no demonstrated health benefits.

So fundamental health reform  reform that would eliminate the insecurity about health coverage that looms so large for many Americans  is now within reach. The “centrist” senators, most of them Democrats, who have been holding up reform can no longer claim either that universal coverage is unaffordable or that it won’t work.