How will Sen. Tim Johnson's illness affect Congress?

Sen. Tim Johnson, D-S.D., was in critical condition but was recovering without complications Thursday morning, following emergency brain surgery. If Johnson were to give up his Senate seat, South Dakota's Republican governor would appoint a replacement, which could swing control of the U.S. Senate.

Guests

• Steven Smith: Director of the Weidenbaum Center on the Economy, Government and Public Policy at Washington University in St. Louis.

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