South Dakota Senator Tim Johnson underwent emergency brain surgery in Washington.
His doctor says he is recovering without complication but remains in critical condition. Incoming Senate Majority Leader Harry Reid visited Johnson in the hospital Thursday morning and said he was confident the Senator would fully recover.
White House Press Secretary Tony Snow extended the White House's best wishes to the Senator and his family. "Our prayers are with Senator Johnson. Look, he's a great guy and it's one of those things that we're all concerned and our thoughts are with his family, friends and his colleagues."