Castro supports a path to citizenship for most undocumented residents of the US, has opposed President Trump's "border wall" plan, and has said that the U.S. Immigration and Customs Enforcement agency needs to be "reconstituted" and that illegal immigration should be treated as a civil offense instead of a criminal one. Additionally, he asserted in the first Democratic primary candidate debates on June 26, 2019 that he would repeal Section 1325 of Title 8 of the U.S. criminal code, which would decriminalize illegal entry into the U.S., rendering unlawful entry a civil offense instead of a criminal one.