According to Trump regime officials who spoke to the New York Times this morning ahead of the DACA announcement, it's possible Trump actually has no idea what he's doing or what will happen next.
As late as one hour before the decision was to be announced, administration officials privately expressed concern that Mr. Trump might not fully grasp the details of the steps he was about to take, and when he discovered their full impact, would change his mind, according to a person familiar with their thinking who spoke on condition of anonymity without authorization to comment on it.
Trump doesn't seem to understand anything about anything so it's plausible that he doesn't grasp the fully implications of ending DACA.
There should be no doubt that Trump himself is a stone-cold racist and that has certainly influenced his decision in this case, but it's also likely that those closest to Trump like Sessions, Miller, and Bannon have told him very tall tales about DACA and immigration in general. Jeff Sessions couldn't even make the formal announcement this morning without lying.
It's also plausible that they haven't been honest about the political and economic consequences of doing this, but you can bet that Trump will blame anyone but himself when everything goes wrong. You can also bet that he won't change his mind because he never apologizes for anything.