The Divide in the support of Clinton and Obama

There certainly has been very discernible divide in the electoral support of Senators Clinton and Obama in the Democratic party presidential nominating contests -- primaries and caucuses. The divide has been along many lines -- gender, race, age, level of education, level of income, and rural versus urban locale -- and some of these divides have been persistent and clear. The enclosed Decision Tree (Source: The New York Times) makes it all evident (you can click on the Decision Tree to enlarge it.)