For their part, Trump supporters often speak of the wall as if it is the alpha and omega of immigration enforcement. Actually, regarding the migrant crisis, changing the rules around how we handle family units from Central America and asylum-seekers would be more important. In general, an E-Verify system to get employers to confirm the legal status of their employees would be the single most effective enforcement measure, by turning off the jobs magnet.

All that said, the White House could have easily secured more funding if it had made it a concerted aim from the beginning. Instead, its initial budget request was for $1.6 billion, which it was on track to get before the president decided that $5 billion was the only acceptable number.

His seat-of-the-pants decision-making is another factor making a good outcome unlikely. He hopes, despite all of this, to wait out the Democrats until they buckle. We wish him luck, but the chances of success would be much greater if wishful thinking were a strategy.