This is more than just an idle question. I will say up front that I am a Hillary supporter. But that doesn't mean that I have blinders on.
Hillary is clearly leading the pack in the race for the Democratic nomination. And this is happening on both the national and state level. As for as I can tell, looking at the state polls there really isn't a single state where she is behind.
That being said, polls are not voting citizens. They are snapshots of people's opinions on the date the poll is conducted. I do think that as more polls over more time show Hillary leading, these multiple snapshots begin to paint a picture that runs over time. And this longer time line of polls is a more accurate representation of how people will vote. Why?
Because each polling period occurs as different information is available about the candidates. They make speeches, put out policy positions, offer up new ideas, back away from previous ideas or positions, and interact with both the media and the voting public. In addition, a debate or forum may have recently taken place. Any of these events offers those polled the opportunity to change their minds about a candidate or re-enforces their support for a chosen candidate.
As the polls continue to accumulate, the fact that Hillary's lead has grown in many of them tells me that those polled like what they see and hear. Of course, peoples minds can change and they do.
As far as Hillary is concerned, I believe only a very major mistake will change peoples view of her. She now has the luxury of taking the high road for the rest of the primary cycle.
On the other hand, Obama and Edwards find themselves in the postion of having to go negative. I know many will say that pointing out issues you differ on is not negative and I would agree. Except that they are not limiting their critisism to policies. They are making it personal - attacking characater. To me that is a loser all the way around.
I hate to see sniping within the party, and it will just be used by the Republicans later on. In addition, it hurts those who level these attacks. My impressions of Obama, though he is not my chosen candidate, is that he is just like all the others who snipe on a personal level. The same goes for Edwards and other candidates who get personal and nasty. I am less likely to support that kind of candidate.
So, back to my question; is Hillary unstoppable? Unless something major happens in this campaign I would say yes she is unstoppable.