Source: Wall Street Journal from data provided by Real Clear Politics.
I love Run Charts! This clearly demonstrates the fallacy of over-reacting to the daily "media data point".
When you take the long view, looking at data over time, the underlying patterns emerge.
Obama's campaign created a massive process shift in Q1 2008, and sustained the new performance level till the end.
Clinton polling data indicates no major shift in polling results, after Obama broke out of the pack in February.