Obama, joined by Mexican President Felipe Calderon at a press conference in Mexico City, said he and Calderon discussed the ban "extensively" during their meeting earlier in the day. Mexican officials have said in recent days that they would like to see the ban reinstated, noting that more than 90 percent of guns recovered in Mexico come from the U.S. The White House was quick to blunt comments Attorney General Eric Holder made earlier this year supportive of pursuing a reinstatement, but Obama said Thursday that he has not changed his position. "I have not backed off at all from...