A letter from a hedge fund manager to his investors about Washington’s policies is stirring up controversy on a sensitive topic among the moneyed elite, The New York Times’s Andrew Ross Sorkin writes in his latest DealBook column. The poison pen of Daniel S. Loeb took a jab recently at one of his former allies, the Obama administration, deploring the redistribution of resources and power that Wall Street has come to fear with the passage of the financial regulation overhaul. Some say that they knew Obama would seek higher taxes and tighter regulation; that was O.K. What they say they...