Donald Trump has dropped 9 points in a national poll following his loss in the Iowa caucuses according to a new survey that will be released Thursday, Business Insider reported. Trump still takes the first spot but received only 25 percent of the vote from Republican primary voters, according to a Public Policy Polling survey.Ted Cruz and Marco Rubio both received 21 percent of the vote, putting them in second place. Ben Carson took 11 percent.In a previous Public Policy Polling national survey released in December, Trump held a double-digit lead with 34 percent of the vote. His closest competitor, Cruz,...