Why are so many Democractic superdelegates stalling?

The impact of the voting public in terms of which candidate will win the most pledged delegates in the primaries has been moot for quite a while now - we've known for some time it would be up to the superdelegates. People were doing the math back in March. Even if Hillary had won big in places like North Carolina and Oregon, the representational "split" of delegates the by percentage of votes virtually assured Obama would end the primary race with more pledged delegates. So if the superdelegates wanted to go with the person with the one who was going to end up with the most pledge delegates, the remaining undeclared superdelegates could have simply sided with Obama and ended the race at any time.

So the issue to me, really, is why are so many superdelegates still on the fence even though Obama has had a virtually insurmountable lead in the pledge delegate count for a while now?

Here are a few reasonable possibilities:

1. If the majority of the remaining superdelegates had simply "gone" for Obama then the last several contests and the few remaining ones would have been meaningless. Some superdelegates may feel that the party is benefitting from increased voter registration and the partisan excitement generated by the historic primary season. Plus, since the race had already lasted so long, letting the remaining voters "have their say" is a popular notion. The potential drawbacks include having the excitement peak too soon (many Americans easily get bored or distracted when it comes to drawn out events such as an entire season of American Idol) and having a schismatic effect spill over from the battle between Obama and Hillary.

2. The superdelegates are politicians, and some of them might prefer to display caution over leadership. In this scenario, the undecided want to make sure how the wind is going to blow, particularly in terms of Michigan and Florida, to avoid any potential political "payback" that comes from backing the wrong candidate. The potential drawback to waiting so long is that their motives will be second-guessed, and since they are the "deciders" of the nominee, this could lead to suspicion about back-room deals and other shady maneuvering which could then fuel the aforementioned schismatic effect into a full-blown rupture.

3. Some of the remaining superdelegates are experiencing a vicarious buyer's remorse concerning Obama and would rather back Hillary, but they don't want to go against the popular grain and haven't found a suitable argument to justify doing so. Hence they are dragging their feet and wringing their hands. The potential drawback here is that Hillary's campaign grows weaker by the day, so stalling only makes backing her that much harder to do.

I am not wishing for the delegates to come out ASAP for a candidate, let alone any particular candidate, although I know many die-hard Obama supporters are. And while the most die-hard Clinton supported might hope that the explanation for the delay by so many superdelegates is something akin to #3, I personally would guess it's mostly Explanation #1 with a pinch of #2 thrown in for flavor.