It's zero hour for health care reform in the U.S. Senate. Republicans hope to defeat the Democrats' attempt to get the 60 votes necessary under Senate rules to bring their bill to the floor. The Republicans believe that if they can defeat the Democrats' plan, either in today's procedural vote or in floor action later this year, it will be President Obama's Waterloo. But that calculation may be wrong.

Running as the party that defeated health care reform does not sound like a winning strategy in next year's congressional elections. Not when more Americans every day are losing their jobs and their health insurance.

A cynic might point out that even if the Democrats' health care bills are a prescription for disaster, the public won't know that for years, perhaps even a decade. That's because it will take that long for the plan to be fully implemented and for the costs to be apparent.

By contrast, voters will know immediately if Republicans succeed in blocking reform.

We do not believe, however, that the Democrats' plan is a prescription for disaster. Yes, it would be expensive, and we don't think that it does enough to cut costs by changing the way health care is financed in this country.

But we do believe it would be an improvement over the way things are now. The Congressional Budget Office estimates that the version of the bill that will be the subject of today's vote will provide insurance to an additional 31 million nonelderly Americans, leaving about 24 million uninsured. (About one-third of the uninsured would be unauthorized immigrants.) The elderly already are covered by Medicare.

The system of subsidies that would help the newly insured people buy insurance would cost an estimated $848 billion over the first decade of the plan's operation. That's a whopping number. But, the net effect of the plan actually would reduce the federal deficit by $130 billion over that same period, because revenues from new taxes on the wealthy and on Cadillac health plans, plus savings from Medicare, would more than pay for the program.

Are these numbers reliable? Probably not. When you tinker with one-seventh of the U.S. economy, it's tough to make precise predictions. But they're the best we've got, and the estimates by the opponents of the plan are no more reliable.

When you roll in the insurance reforms -- no more denial of coverage for pre-existing conditions, no more discrimination on the basis of gender -- the plan looks even better.

Sure it's a gamble. But when tens of millions of Americans are uninsured, it's one worth taking. Republicans should consider that.