The surge of Central American families and unaccompanied children into south Texas has focused public attention on one of the few recent revisions of immigration law, the 2008 Trafficking Victims Protection Reauthorization Act, or TVPRA, also known as the Wilberforce Act. Championed by congressional Democrats such as Senator Dianne Feinstein, the law was a hastily written attempt to improve the handling of trafficked children who came into the custody of immigration authorities, either at the border or within the country. In the face of public alarm over the Obama administration’s massive catch-and-release operation dispersing tens of thousands of illegal border...