Immigration reduction refers to a social movement in the United States that advocates a reduction in the amount of immigration allowed into the country. Steps advocated for reducing the numbers of immigrants include advocating stronger action to prevent illegal entry and illegal immigration, and reductions in non-immigrant temporary work visas (such as H-1B, L-1 and J-1). Some advocate tightening the requirements for legal immigration requirements to reduce numbers, or move the proportions of legal immigrants away from those on family reunification programs to skills-based criteria. What separates it from standard immigration reform is that reductionists see immigration as a major source of social, economic, and environmental problems, and seek to curtail current immigration levels. Many immigration reformists only oppose illegal immigration and support continued legal immigration methods. Some immigration reductionists want to maintain current legal immigration percentages until fewer adverse effects are created by legal immigration. The related terminology "self-deportation" or "to self-deport" refers to the viewpoint that through social policy illegal immigration to the U.S. can be reduced by causing residents to leave the U.S. on their own, thus creating a reduction. In 2016, Donald Trump ran for president as a Republican. His campaign featured rhetoric and policy proposals that were strongly anti-immigrant. His proposals found broad support in the U.S. heartland and the Southern United States, although they were criticized by Democrats and some Republicans as racist, xenophobic, and Islamophobic. Trump won the election and enacted multiple anti-immigrant policies as president. Nativism There have been several discernible groups at various times within the United States, which pushed for immigration restrictions, with separate concerns, origins, and aims; thus there are several antecedents for the modern immigration reduction movement. These include the nativist United States American Party, often called the Know Nothing movement of the mid-19th century, which objected to increased Catholic immigration of predominantly Irish and German origin; the Workingman's Party which objected to immigration laborers from China to California during the late-19th century, a sentiment that ultimately led to the Chinese Exclusion Act of 1882; the Immigration Restriction League, which objected to greatly increased immigration from southern and eastern Europe during the late-19th and early 20th centuries, and the joint congressional Dillingham Commission, which studied this latter complaint and proposed numerical restrictions. Eventually, following World War I, these studies led to the Emergency Quota Act of 1921 and the Immigration Act of 1924. Labor unions Organized labor generally