A new poll by a right-leaning consulting group released Dec. 22 shows Sen. Ben Nelson trailing a pair of potential challengers for the Senate seat in 2012. Magellan Data and Mapping Strategies — a firm that claims to offer data solutions for the GOP — commissioned the poll of 1,789 “likely 2012 voters” and found Nelson’s overall approval rating at 43 percent. The poll also showed that 52 percent of voters favored Nebraska Attorney General Jon Bruning in a race against Nelson (38 percent), while 46 percent favored State Treasurer Don Stenberg over Nelson (40 percent). An earlier poll commissioned by the Nebraska Republican Party showed Bruning with a 15 percent edge over Nelson in November. Bruning announced Nov. 5 that he had formed an exploratory committee to evaluate a run at the Senate in 2012. Stenberg also said in November that he is considering entering the race. The margin of error of the poll is 2.3 percent.