Max Baucus

Montana

Baucus, 64, will preside over domestic issues that the White House regards as crucial, including tax policy and the future of the fragile Social Security system. Baucus, sometimes to the consternation of his fellow Democrats, has a tradition of working closely with his Republican colleagues on major pieces of legislation.

Baucus, who comes from a well-known ranching family in a Republican-leaning state, has served in the Senate since 1978. Soon after President Bush took office in 2001, calling for large tax cuts, Baucus and the Finance Committee chairman, Charles E. Grassley (R-Iowa), worked together to produce a bipartisan tax package that was not viewed favorably by the chamber's Democratic leadership.

Two years later, Baucus and Grassley also worked closely on legislation to add prescription drug coverage to Medicare, the biggest expansion in the history of the federal health insurance for older Americans. Baucus was one of only two Democrats allowed by House GOP leaders to negotiate the final bill, and it created a bigger role for private insurance companies than his party wanted.