It isn’t complicated. He’s pointed out the bleeding obvious and stated an unambiguous position.
For this ‘crime’ the full might of the DC swamp creatures has been unleashed upon him.
How is it unambiguous? He says he wants illegals to stay? He is a trial balloon to show that the left can win with a liberal candidate if the can con enough people with sounds bites. He represents total victory for the left.
Here's why I think he's doing so well: When he makes a statement on an issue like illegal immigration, he stands by that statement and doesn't back down when the left subsequently attacks him for saying what he said. Just about any other Republican would immediately back track, apologize profusely, and beg the left for forgiveness (which, of course, is never granted.) I don't know who will win the nomination, but could you imagine what would happen if the entire Republican field took the same approach, and stood up to the left the way Trump has been doing? The liberal loons in this country wouldn't know how to handle it! Their heads would explode!