US immigration restriction laws were explicitly justified by eugenic racial science

Evidence

Like today, immigration policy was a race issue. Relying on eugenics, the Dillingham Commission’s Report recommended that immigration from Southern and Eastern Europe be severely curtailed because of racial difference and inassimilability. … All men are born with equal rights has been confused with the political sophistry that all men are born with equal character and ability to govern themselves and others, and the educational sophistry that education and environment will offset the handicap of heredity.” As a result, the American nativist movement labeled Celts, Italians, Hebrews, and Slavs an inferior stock of Whites that warranted their exclusion from American shores. — Sahar F. Aziz, The Racial Muslim, 241

Categorization

• QUESTION: The eugenicist’s phrasing equates ‘equal rights’ with ‘equal ability.’ Does Aziz later trace how this same slippage recurs in arguments about Muslims and citizenship?
• XREF: connects to: Eugenics supplied scientific legitimacy but no racial typology to nativism — John Higham, Strangers in the Land: Patterns of…, 911; Restrictionists saw even the 1890 census scheme as artificial and sought direct racial preservation — John Higham, Strangers in the Land: Patterns of…, 1937