When Donald J. Trump launched his presidential bid in 2015, he promised: "I will build a great, great wall on our southern border. And I will have Mexico pay for that wall. Mark my words."' He often repeated this promise at campaign rallies, sparking chants of "Build the wall! Build the wall!" from an ecstatic crowd. However, as of early 2020, Trump's wall has not been built, Mexico has refused to pay for it, and the likelihood that the wall will be built has decreased significantly. So far, only a handful of highly-touted wall prototypes have been erected and hyped to the American public as a cure-all for what President Trump has deemed as the United States' social ills. In February 2019, he responded to challenges he has faced in building the border wall by declaring a national emergency to obtain funds to pay it-a measure contested in federal court.