President Trump's announcement that he will rescind an Obama-era executive action providing legal protection to people brought to the U.S. as children has all the appearances of a final decision. But it's actually just an opening bid. By including a six-month delay before the end of the Deferred Action for Childhood Arrival program, Trump gave Congress a narrow but achievable window to spare the Dreamers. There are signs that Republicans in Congress may want to prevent the deportation of nearly 800,000 individuals who have taken advantage of the program to get drivers licenses, go to college and launch careers. Speaker...