Trump has pledged to reduce immigration. But by narrowing the already limited legal pathways into the U.S., migrants will just recalibrate their plans and resort in greater numbers to hiring smugglers, experts say. In many cases that will mean turning to organized crime groups that increasingly profit from migrant smuggling.

The U.N.’s International Organization for Migration estimates there are around 281 million international migrants in the world, or 3.6% of the global population. An increasing n