WASHINGTON -- The chairman of the Senate Finance Committee on Wednesday will release a sweeping proposal to overhaul the health-care system that largely reflects President-elect Barack Obama's vision, increasing the chances for action next year.

There is one important difference between the initiative coming from Montana Democratic Sen. Max Baucus and the plan Mr. Obama laid out during his presidential campaign: Mr. Baucus would require all Americans to have health insurance, while Mr. Obama has rejected the idea of a mandate.

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