Ted Kennedy, battling brain cancer, strikes exactly the right balance in his letter (pdf) to state officials on how his seat in the U.S. Senate should be filled.

In a story broken by the Boston Globe’s Frank Phillips, Kennedy endorses a 2004 law that took away the governor’s ability to fill a Senate vacancy and gave it to the voters instead. But Kennedy also calls for an amendment allowing the governor to appoint an interim senator who would serve during the five-month period preceding the special election. Finally, Kennedy suggests that the governor appoint someone who promises not to seek election.

The law was changed five years ago when it looked like Sen. John Kerry might be elected president. Legislative leaders wanted to make sure that then-governor Mitt Romney, a Republican, would not have the ability to choose Kerry’s successor. Once and future Romney spokesman Eric Fehrnstrom refers to that on Twitter today:

Wishing Dems now calling for Gov to appt Kennedy replacement stood with Romney in 2004 when they took that power away from him.

(Fun random fact: I ran into Fehrnstrom on the summit of Mt. Monadnock recently.)

But Democrats did the right thing then, even if it was for partisan reasons. As Kennedy suggests, they should leave the law alone, but not let the seat go unfilled for five months.

The wisdom of the 2004 law was proved after President Obama’s election last fall. First, then-Illinois governor Rod Blagojevich disgraced himself and his office by putting Obama’s Senate seat up for sale — an action that led to federal corruption charges against him. The appointment went to the supposedly incorruptible Roland Burris, who turned out to be highly tainted himself.

Then, after Obama named Sen. Hillary Clinton of New York as his secretary of state, Gov. Donald Paterson turned the appointment of a successor into a circus, using anonymous aides to smear Caroline Kennedy, who wanted the job but was clearly unprepared. The post eventually went to an obscure Albany-area congresswoman, Kirsten Gillenbrand.

No one is suggesting that Gov. Deval Patrick would pull a Blago or even a Paterson. But senators should be elected, not appointed, as has been the case since the 17th Amendment took effect in 1913. Kennedy’s proposal honors that proposition while plugging an unnecessary gap.

Photo of Kennedy (cc) by Will White and republished here under a Creative Commons license. Some rights reserved.