Attorney General Jeff Sessions, who has endured a rocky relationship with Donald Trump for months, has issued his strongest pushback yet against the president, saying in a statement Thursday that the Department of Justice "will not be improperly influenced by political considerations."When asked whether he will "fire Sessions" in an interview that aired on Fox News Thursday morning, Trump took aim at his attorney general, with whom he has waged both open and low-level warfare since Sessions recused himself from the Russia probe early last year.