Trump has never really had a “stance” on anything except, “I am awesome and I will say anything to get heaps of adulation from you.”
This includes illegal immigration. He was quick to get the rabid right on board with a very hard line, but his (new) handlers have apparently convinced him that he needs to expand his base, so he needs to appeal to different groups. But we all know that even if by some miracle he gets elected President, he’s not going to build a wall, nor is he going to create a path to citizenship. He’s going to keep the status quo, unless his handlers tell him otherwise.
You can say pretty much the same about all the other issues he’s flip flopped on (practically all of them) — a ban on Muslims, bombing the “oil fields of ISIS”, cutting taxes on the wealthy, abortion, LGBT rights, minimum wage, nuclear weapons, and many more. Here’s a list: http://www.nbcnews.com/politics/2016-election/full-list-donald-trump-s-rapidly-changing-policy-positions-n547801