Behind the scenes there are some Democrats becoming concerned that Hillary Clinton is pursuing a wrecking ball strategy in which she knows she will not defeat Barack Obama for the nomination, but will escalate personal attacks in the hope Obama loses in November, so Hillary can run in 2012.
This is not a widespread view, and I am not suggesting it is true, but there are some who are worried about this, which is one reason superdelegates could move en masse to Obama, very quickly.
Hillary Clinton must be very careful. This view will not in the end defeat Obama, but it could do major long-term damage to both Clintons.