You have to have a legal basis to file a lawsuit. You can't just file a lawsuit because some policy is "egregious." "Egregious" policies are legal as long as they don't violate a law or a constitutional provision. "Egregious" laws are legal as long as they don't violate the Constitution. But let's say you're successful in court, who enforces that decision? The very administration you're suing to stop the egregious policies. It's heads you lose, tails you lose. Don't count on the courts to bail us out.