Congressional budget crunchers Thursday said the Democrats' latest health care plan would hold down federal red ink for at least a 20-year stretch, an assessment that boosted the bill's advocates as the Senate moved gingerly toward a historic debate.

The nonpartisan Congressional Budget Office said that Majority Leader Harry Reid's 10-year, $848-billion bill would produce a net reduction of $130 billion in federal deficits in its first decade. Perhaps more significantly, the legislation would continue to give back over the next 10 years and beyond, the budget umpires said, because "added revenues and costs savings would probably be greater" than the cost of covering uninsured Americans.

The budget office put a big asterisk on its forecast, using words like "imprecision" and "uncertainty" to describe the long-range projection. It noted that, overall, health care spending remains on an unsustainable path.

However, the bill would not make matters any worse, and maybe even a little better.

With President Barack Obama pledging to tamp down ruinous health care costs, Democrats took the new CBO estimates to the bank, while skipping over the caveats. Preparing for a noontime rally with supporters, Reid, D-Nev., said the legislation would "save lives, save money and save Medicare."

The CBO said Reid's bill would extend coverage to 94 percent of eligible Americans, after subsidies to make premiums more affordable start flowing in 2014. That's one year later than in the House Democratic bill — and well into the next presidential term. Postponing the subsidies by one year allowed Reid to offer somewhat more generous assistance to defray the cost of insurance premiums.