After a frazzled week, the politics of US health reform looks messier than ever. Yet the odds on a bill passing in the end are improving. It will be an untidy thing, but if it moves the country close to universal health insurance the administration will call it a success. And on the whole, despite the avoidable mistakes this legislation seems bound to embody, that will be a fair assessment.

At the moment this view may seem unduly optimistic. The Democratic leadership in the House of Representatives had hoped to produce a finished bill last Friday. That plan came to nothing when the party's fiscal conservatives demanded further savings. House Democrats are also divided on revenue-raising measures. Proposals ranging from a fat tax on sugary drinks to a fat-cat surtax on households earning more than $250,000 (€179,000, ￡154,000) a year are still being debated.

The Senate is struggling with the same issues: how to contain the cost of expanded insurance coverage, and how to pay for what remains, so that the reform adds nothing to the budget deficit over 10 years. Like the House, the Senate aims to broaden coverage with a mixture of mandates, regulation and subsidies. Those basic elements are decided. But at the end of last week the chairman of the Senate budget committee said that the bill's drafters would have to start all over on key aspects of the proposal.