A new documentary makes the controversial case that a political cocktail of big corporate money and racially charged sentiments has helped fuel the rise of the tea party. And squarely behind that movement, the film argues, are the Koch brothers. Co-Directors Carl Deal and Tia Lessin sat down with “Top Line” to discuss their film, “Citizen Koch,” and why they say the GOP’s deep-pocketed donors, the Koch brothers, are such figures in American politics today. “Money – $100 billion now,” Deal said in explaining the Kochs’ influence. “When we started out making this film, their net worth was about $68...