Discretion is not mandatory - how will they successfully sue?? That was the problem with DAPA - they did not successfully challenge it and it was modeled after Daca. Judge Hanen stated that the govnmt had the right to discretion to not pursue deportation, but the do not have to grant benefits. That means your EAD. That was the problem.
This is just political gamesmanship.
Stop playing w ppl's lives. Offer DreamAct as an amendment to Harvey relief, then reconcile with the overall budget.