It's been said by Trump and some of his supporters that illegal border crossing has lessened since Trump took office, going down by about 40%. If that is true, then why is Trump still wanting to build the "WALL"?

He's so irrational, he hasn't given any thought to how much it will cost. As usual, he just blunders everything he is trying to do. So far, Trump has not accomplished one thing that he has promised to do.