Senator Ted Kennedy, who is gravely ill with brain cancer, has sent a letter to Massachusetts lawmakers requesting a change in the state law that determines how his Senate seat would be filled if it became vacant before his eighth full term ends in 2012. Current law mandates that a special election be held at least 145 days after the seat becomes available. Mr. Kennedy is concerned that such a delay could leave his fellow Democrats in the Senate one vote short of a filibuster-proof majority for months while a special election takes place.

"I...