Immigration Crackdown Is Full of Economic Holes: Jonathan Levin (1)

Like it or not, parts of the US economy depend on undocumented and other low-wage immigrant workers. The system has evolved to assume they would always be here, especially in areas such as agriculture, hospitality and construction. You can’t strip them of their status, deport them or scare them into the shadows without unleashing a wave of complications. It’s no wonder that President Donald Trump is second-guessing his immigration policy, with enforcement guidance changing erratically every few days.

The flip-flopping has been on display before the nation. One week, he’s announcing enforcement carve-outs for key industries and political constituencies. The next, his administration ...