The focus on undocumented and low skill immigrants allows Trump to claim that they are more likely to be drug traffickers and violent criminals like MS-13. In fact, studies have found that the presence of immigrants is either not associated with increased crime rates or is related to a decrease in crime. According to the U.S. Border Patrol, of the annual influx of the 45,400 undocumented and unaccompanied minors entering the U.S., about 56 are suspected or confirmed as MS-13 gang members. In contrast, there are about ten thousand MS-13 gang members in the U.S. spread across 40 states. There is no evidence supporting the claim that undocumented or low skill immigrants increase U.S. crime.
In part, because immigrants face stringent eligibility requirements for public assistance they use less than the native-born. Moreover, when immigrants receive benefits, the value of the benefits they receive is usually less than that obtained by the native-born. The combination of less use and lower benefits means the overall cost of public benefits is substantially less for immigrants than for comparable native-born adults and children.
Undocumented immigrants pay an estimated $11.2 billion dollars in state and local taxes. Besides state and local taxes, the bulk of which is made up of sales and property taxes, undocumented immigrants are estimated to have paid $23.6 billion dollars in federal income taxes. About half of all undocumented immigrants pay taxes in the hope that their tax records will, at some point, be used to show how long they have been in the U.S. and to help them obtain legal status. Also, low-skilled immigrants, including the undocumented, help lower the prices paid by consumers for services in large cities with immigrant populations.
Furthermore, immigrants will be needed to make for the loss to the labor market of retiring baby boomers. Immigrants, including undocumented immigrants, are already contributing to the Social Security and Medicare of native workers and will be needed to provide more in the future. According to the Social Security Administration, undocumented workers contributed $13 billion dollars to Social Security, although most will never benefit from their contributions.