WASHINGTON -- White House hopeful Barack Obama was on the defensive Wednesday over stock purchases from companies whose investors included his political donors. And Obama revealed that he terminated a "quasi-blind" trust he created for the stock purchases -- called the "Freedom Trust" -- after realizing that it wasn't blind after all. Obama's campaign team ramped up a rapid reaction defense after a story about his portfolio hit the front page of Wednesday's New York Times and was the subject of scrutiny Monday on thestreet.com. Denies any connection The political damage potential is high because one of the firms Obama...