Senator Edward Kennedy is dying of brain cancer. On a personal level this is a tragedy with which I can empathize as my father also died of brain cancer. However Kennedy is not just a private citizen he is also a public servant with important duties which he is increasingly unable to discharge. If Kennedy does not resign then under Massachusetts law his seat will remain vacant for at least 145 days after his death while a special election is held to replace him. This could deny the Democrats a critical vote on important legislation. On the other hand Kennedy could resign now effective at a future date. This would start the special election process and minimize the length of time his seat is vacant. In my view it is his duty to his country and his party to do this.
Somewhat ironically the Democrats changed the vacancy procedure in Massachusetts in 2004 so that then Governor Romney could not appoint a interim replacement should Senator Kerry have been elected President. This change may come back to haunt them.