Democrats may actually keep their majority in the US Senate, even if Senator Tim Johnson remains incapacitated following brain surgery, a Senate historian told AFP, noting that over the years a few lawmakers have retained their seats despite prolonged illness.

"The Senate has never vacated a seat because of the illness of a senator," said Senate associate historian Donald Ritchie.

"The Senate has the authority to judge the qualifications of all of its members, and it could, if it chose, declare a seat vacant," he said. "But in the past, we’ve had senators absent for several years, and the Senate has never acted to vacate the seat."

Ritchie recalls a 1969 incident in which another South Dakota senator, Republican Karl Mundt, had a stroke. Incapacitated, he left Washington but remained officially on the job up to the end of his term in 1972, without ever being present for a vote during that period.

Mundt offered to resign on the condition that the state governor — who has the authority to appoint a senator between elections when the seat is vacated — name his wife to replace him.

And before Mundt, there was Virginia Democrat Carter Glass, a senator who was absent from Capitol Hill from 1942 up until his death in 1946, due to heart problems.

Ritchie could only point to one example in which a sitting ailing legislator — not from the Senate, but from the House of Representatives — left, but under very different circumstances.

Longtime Maryland congresswoman Gladys Spellman, a Democrat, suffered a heart attack in 1980, just before Election Day, and since she was in a coma, she was unable to take the oath of office in January 1981.

Her family asked House officials to declare the seat vacant, and a new election was held.

Copyright © 2006 Agence France Presse