The difference is that people are already calling Cruz out for flip flopping on immigration. But everyone still says that Trump is a hardcore conservative on immigration and has always been that way. I just pointed out with this article that that's not the case.
He was saying a bunch of things contemporaneously. He also said in 2013, that there would be '11 million people will be voting Democratic' if amnesty was granted. Still, notice the context, he attacked 'self-deportation', not deportation, per se, Cruz attacked both self-deportation and deportation.