The more I see on Susan Rice, the more I agree with those (a small minority) who think the Senate Republicans really played a trick on the left by flagrantly opposing Susan Rice. (Or more likely - as they had a vested interest in making an issue on Benghazi and McCain had many reasons to dislike Rice from the past and she has,at best, mediocre relations with people in the Senate - the left faced with a Republican attack assumed that if the right hated her, she had to be the choice of the left. Additionally, the fact that they signaled what EVERYBODY already knew that Kerry was respected by almost all the key Republican leaders led the left to assume that either they just wanted a chance at the seat or that Kerry was the DINO/Republican acceptable choice.
In fact, one article hit one thing on the nail - that one possible concern with Kerry was that he had an "independent streak". Our words for that were that he has integrity, core beliefs and a conscience that he generally follows - even when it is not the politically wise thing to do. I also saw a 2009 article (that I can't find now) where Kerry spoke of having his independence and a position to impact fp as Chair - saying that there was a trade off and that he was ok with what he had. (It was jarring reading these two near the same time - with the connection being independence.)
In addition, on issue after issue, he is closer to the left's values than either Hillary Clinton or Susan Rice. ( All you have to consider is who was where on Keystone and on Honduras. Not to mention, neither would have done what Kerry did on the Contras or BCCI. ) It is ironic that one legacy of 2004, where the left never saw that Kerry had a more sterling left background than Dean, is that Kerry, who should be a hero to the left is lumped with centrists like the Clintons, but liked less than they are! More ironic is that the very conservative Gore is still iconic on the left.
To me, this choice will tell me a lot about Obama. Oddly give the left's position, choosing Rice will to me look like one of the following - cronyism or wanting to avoid another strong competing voice ( I think if both were in the NS team Kerry would be often allied more with Biden and, in fact, would likely influence Biden. )