From the Religion News Service [Texas Star-Telegram sub. required]:
Religious conservatives are always ready to mistrust the elite educational, cultural and political institutions of our nation, and they often draw on that mistrust in seeking to galvanize their own constituency.
Roberts appears to be a person who has managed to come through such institutions, gaining the greatest value possible from them while retaining recognizably conservative religious, moral and political values. This kind of person could help bridge the red-state/blue-state cultural divide and symbolize that it need not be an eternal or immutable division.