Very good observation! She did start very very early. In fact, that was the earliest election I'd ever seen.
We must also consider the fact that the media picked Obama over Hillary. Whether she entered early or later Hillary should have been and would have been the nominee if the media did not carry the water for Obama. Obama is the media's President.
I’ll never forget the tears of joy on Carl Cameron Fox News’ face when Obama won. Even the so called conservatives in media seemed to be jumping for joy.