DUmmtards, the Oministration wouldn't let this go forward if they thought it was going to hurt them. These are fully-adjudicated cases with outstanding deportation order that are being ignored up until now.
The objective is obviously to appear to be 'Not sleeping at the switch after all' to the moderates, and keep them from fleeing to Trump or other immigration hard-liners. The big question is whether the political calculus is correct on the Left; it's based on the legalistic assumption that since these cases have already been adjudicated, there should be no problem with their own base. This assumption, in turn, is based on the rash assumption that the Leftist base thinks rationally and accepts the legality of any government action that runs counter to their emotionally-driven positions.
Now if the Left reacts like the berserk emo retards that they really are, I would not be surprised to see ICE (At the behind-the-scenes instigation of the White House) 'Reconsiders' or scales down this thing. If that happens, the Leftist base will be only slightly mollified, but the Center and Right will have even less confidence in Democrats controlling the border than they already do.