Threadline makes it sound that way, but I think we're overreacting. Her point is that Kennedy was a contender late in the nominating process, so it is not a given that she must drop out.
I hate to be a Hillary defender, but I have to agree. It's pretty clear from listening to the interview that she is NOT in any way suggesting that she is staying in the race in case Obama gets assassinated.
She is giving several historical examples to show the folly of people clamoring for a quick end to the nomination contest.
She (unwisely, no doubt) uses Kennedy's death as a well-remembered time marker to make the case that nomination contests have in many cases gone on well into June.
In print it looks bad ... and it may hurt her big time. But her interviewers did not do a double take at all. It was pretty clear what she was trying to say.
I had the same reaction. It was an unwise remark, and may even have revealed some wishful thinking on her part, but I agree with your interpretation. That said, I wouldn't mind if her political career died a permanent death as a result!