This isn't a blow to the Trump administration, it's an opportunity. Congress can't or won't act, and the task for the Administration is to get this off its plate so it doesn't remain an issue come November. So accept the order - allow the 700,000 who came forward to continue to participate in the program, and shut it down for everyone else. That allows Trump to paint himself as compassionate and fair to those who've stuck their necks out, and to pander to his base by keeping the program strictly limited to the 700,000, with no path to citizenship.