Barriers to a Border Wall

Although the latest spending bill did not include funds for it, President Donald Trump is not backing down from his pledge to build a nearly 2,000-mile wall along the Mexican border. Designs are being solicited, and construction of prototype barriers is scheduled to begin in San Diego this summer. But fulfilling Trump’s signature campaign promise won’t be easy. Mexico says it won’t pay, Democrats are opposed, and even GOP allies suggest a wall spanning the full border is unrealistic. Here are some other challenges facing the project:

More From TIME Magazine: