if this was entirely political, i'd just ignore it as opportunistic - and concede it will probably work.
but, these arguments are not even close to being correct, they're in truth barely even formed, and should the case get to trial (which it probably wouldn't; these arguments are so bad that the case could and probably should be dismissed) they could have a devastating impact on the ability of future presidents to pass similar legislation.
the only possible outcome of this trial is to place future legal restrictions on what the president can't do.
migrant rights activists should be opposing this suit, due to the dangers of these unforeseen consequences. and, i will publicly call for these states to withdraw this response as poorly thought through, and even to apologize for putting the lives of migrants at risk.
this has to be dealt with in congress. you can find any number of clips by obama himself, pointing that out. and, it may perhaps be useful to get a recent statement on the topic from the former president, who has an opportunity for responsible civilian leadership in front of him.
it's been known for years that the votes exist in congress, but the congressional leaders couldn't put it to a vote. paul ryan, at the least, has changed his mind. the focus needs to be on targetting mitch mcconnell, to make sure he puts the legislation through.
http://www.cnn.com/2017/09/06/politics/daca-trump-states-lawsuits/index.html