his much-promised border wall. i am proud to shut down the government for border security, chuck. reporter: the move will put funding the government into the hands of newly empowered democrats next year, while effectively closing the door on one of the president s loudest campaign promises. build that wall! do not worry. we are going to build the wall, okay? reporter: three sources close to the president tell cnn he has become increaseingly sensitive to breaking the promise. it would have been just a joke presidency that scammed the american people, enraged amused the populus for a while. but he ll have no legacy whatsoever. reporter: the fight over the wall has created a bitter divide inside the west wing. between aides who consider themselves pragmatists and those who are ideologues. sources tell cnn, steven miller, a hard liner on immigration,