Sen. Tim Johnson [3] (D-S.D.) is recovering from surgery at George Washington University Hospital to stop bleeding in his brain caused by an arteriovenous malformation, a condition which causes arteries and veins to grow abnormally large. Johnson's condition was described as "critical" by hospital officials early this morning. Around 9:30 a.m., an attending physician described the surgery as "successful" and stated that Johnson was "recovering without complication." He added, however, that it was "premature to determine whether further surgery will be required or to assess any long term prognosis." He was first hospitalized late yesterday morning after suffering from stroke-like symptoms on Capitol Hill. Johnson, 59, is a two-term senator whose current term expires in two years.

With the partisan balance in the Senate so close, there could be strong implications if Johnson's seat is vacated. The Seventeenth Amendment [4] of the Constitution [5] declares that when Senate vacancies open in a state, “The legislature of any state may empower the executive thereof to make temporary appointments until the people fill the vacancies by election as the legislature may direct.” Under South Dakota law, a special election is to be called when a seat is vacant, except when the vacating member's term is up during the following election cycle. Because Johnson is indeed up for reelection in 2008, South Dakota Secretary of State Chris Nelson said, "If there's a vacancy, the governor (Republican Mike Rounds) appoints a replacement who serves until the next general election." If Johnson's seat became vacant and Rounds chose a Republican for the slot, the Senate would become split evenly between Democrats and Republicans. Because Vice-President Dick Cheney [6] would cast tie-breaking votes, the Senate would officially revert to a Republican majority. According to the Senate historian, Richard Baker, vacancies can occur only "by death or resignation." He added, "Nobody has the power to determine a vacancy for a person who is still living."

The Senate last faced a situation such as this in 1969 when Sen. Karl Mundt, a Republican from, ironically, South Dakota, suffered an incapacitating stroke. In that case, Mundt remained in office until his term expired in January 1973. Mundt was pressured repeatedly to step down during his illness, but he refused because the sitting governor refused to meet his demand that the governor appoint his wife to fill the seat.

Stay tuned to Congresspedia [7] for updates on Sen. Johnson’s condition and its implications on the 110th Congress [8].