I think Matthew Ygelsias' piece about how Republicans have learned to like having a checked-out ignorant President. It makes him easy to manipulate and that is why this "new kind of Republican" who ran on economic populism has an administration that is running thing like a regular old right-wing Republican giving tax breaks to the ultra-rich. But that scenario gives the Trump administration a unique vulnerability.
Trump famously hated it when it became common wisdom that Steve Bannon was really calling the shots. All the jokes about President Bannon and even the fact that Bannon got top billing in the title of this book supposedly contributed to Bannon's marginalization and loss of influence within the Administration.
So let's keep talking about how President Trump is being manipulated by Steven Miller and other immigration hard-liners. If the buzz is all about how the President is being taken advantage of by those guys, Trump is going to try to prove that isn't the case. One way to do that would be to strike that DACA deal.
An easily manipulated president is extremely dangerous for the country and the world. But it is who we have. We might as well try to use it to our advantage as well.