Well... people who result to ad hominems when they run out of arguments probably shouldn't engage in threads, legal or otherwise.
It couldn't possibly be simpler. The Constitution limits the President's powers. Immigrants have the right to petition the US courts when they have a dispute with the US government. One of the arguments they can make is that the President has exceeded his authority.
It is simple, but you don’t get it. We are not talking about people in the US who have been admitted by law. We are talking about citizens of Pakistan In Pakistan and whether they can sue to be allowed to force the US to admit them. Two very different things.