The reason Elizabeth MacDonough gave for ruling against including immigration reform in budget reconciliation is pretty sound and strong. If democrats can give GC to a certain subgroup with 51/49 senate majority without 60 votes now, tomorrow republicans can rescind GC to certain subgroup with same 51/49 senate majority. It is against a law. It will set a bad precedent and is like opening a pandoras box. There is no alternatives to counter this reasoning. Schumer is only saving his face.