Five years ago he persuaded the Massachusetts Legislature to change its law regarding filling a vacancy in its US Senate seat. He did that in case his junior counterpart won the Presidential Election that year; Mitt Romney was Governor at the time and Kennedy didn’t want him to name Kerry’s replacement, had he won.
Now that he’s dying, he wants the law changed back to the way it was beforehand: the Governor (who is, of course, a Demo☭rat) appoints the successor immediately. He’s doing this to preserver his Party’s filibuster-proof majority, pure and simple.
Mary Jo Kopechne was unavailable for comment.

Gosh, do you think that would also work for Президент Оба́ма? Oh darn, that’d make us Racists!