I don't think it's just the video medium though... The Clinton campaign didn't find its voice until we saw how hard Hillary was fighting and were reminded how hard she had worked to get there, representing all the women.
Obama, meanwhile, had a very simple and clear message. Change. How refreshing amidst all the economic, social and political chaos! His videos and speeches are so emotional, you feel you are part of his movement just by passing it along. I am not even an American citizen. I cannot vote. I have to admit I felt drawn to his story as someone who lives here and has family affected by US politics in North America and abroad.
Obama said what was on everyone's mind. The Web made it loud enough for everyone to hear. An authentic message, powered by passion and emotion, distributed by 1's and 0's.