People who are serious about immigration have identified all of these as top priorities. Senator Tom Cotton’s “RAISE” bill addresses them. The hope always was that regularization of DACA beneficiaries would become part of a larger package that would tighten enforcement, cut overall intake, and rebalance the lawful flow away from family chain migration and toward ultra-skilled workers and researchers.

But Donald Trump’s interest in immigration is fixed on one big object: finding a way to honor his promise to build a Great Wall of America along the Mexican border.

The truth is that border barriers can play an important role. The 1990s-vintage fencing between San Diego and Tijuana cut illegal migration at that crossing point. But there are hundreds of miles of Mexico-Texas border that get almost no traffic even unfenced—and where concerns over private property, the environment, and plain value-for-money make a physical wall a ludicrously pointless notion.

But Trump, himself a notorious employer of cheap foreign labor on his building sites and at his Mar-a-Lago resort, has never been interested in immigration as an issue, only as a means to mobilize political emotion. And so he now seems to have fastened on the concept of trading some update of the Dream Act to secure Democratic votes for the Trump Wall.

As so often, he did not think it through. Democrats have no incentive to make his deal—and every incentive to thwart it. If Santa asked Minority Leaders Nancy Pelosi and Chuck Schumer what they would like most for Christmas this year (Trump is president now, so we can say the word “Christmas” again), they might reply: “Some spectacular deportations of people brought to the United States sometime during the 2018 congressional cycle would be perfect.” Trump’s call on Congress to do something—who knows or cares what?—about DACA by spring of 2018 is a formula to unite Democrats, split Republicans, and achieve nothing. It puts the immigration spotlight on precisely the GOP coalition’s weakest point, in the misplaced hope of getting ungettable votes for the GOP’s dumbest idea.

The right course was to make a priority of the RAISE Act—and to include legalization of the DACA beneficiaries as a subprovision within RAISE. That would be a heavy enough lift, since not all Republicans support RAISE, and since the party’s biggest and most influential donors almost unanimously oppose it. But if a difficult plan, it would be at least a plan. What Trump has offered instead is a gambit leading to disaster.

The administration has announced the imminent end of DACA unless something is done by Congress.

The administration will fumble any attempt to provide leadership of that “something,” as it previously fumbled health care and will fumble tax reform next. It’s hard for an administration to lead when the president does not care about policy, when the White House staff spends its days knifing each other, and when actual policy expertise is a disqualification for White House employment.