The Immigration Act of 1924 is a legal artifact of a conservative decade. The 1920s were a period that saw an intense backlash to the progressivism and social changes of the previous decades. Most notably, this law barred immigration from virtually all Asian nations, not just China.
Before this, the Chinese Exclusion Act of 1884 limited labor migration from exclusively that national entity.
The 1920s successor law targeted a larger global region, as well as parts of the Global South. It happened through the development of a quota system which made it possible to limit the migration of certain origins to the United States by only allowing two percent of the total number of a nationality already residing in the United States. The census data used for the law was from the year 1890. Obviously, the law limited certain regions of the world while incentivizing other regions.
Sadly, these developments also correlate with a larger racial panic that characterized a potent eugenics movement within the United States. It was fueled by fears of immigrants from Southern and Eastern Europe, the migration of African Americans from the oppressive Southern states, and the nation's entrance into a global war that made Woodrow Wilson deem the United States citizens "provincials no longer."
The xenophobic gene has always been in America for we are as human and as flawed as other present and past societies. It is irresponsible when national leaders use immigration as a political cudgel for their own careers rather than foster a nuanced conversation in regard to the vitality gifted to the US by its immigrant populations. Responsible leadership also means discussing border policy as an evolving discussion that needs to be effective and enforceable conclusions.
The Republican party of today is ground zero for rank demagoguery. However, the industry of politics can muddy our civic duty and democratic responsibility and allow us to not think about these topics with clarity and openness. Sadly, this happens all over the political spectrum, however, the demographics and incentive structures within the GOP make a rational conversation impossible to be had inside the Republican camp. A fake news channel owned by the Murdoch family further pollutes that internal and external discussion when it broadcasts nothing but skewed (and frankly race baity) coverage of the southern border all day and night.
The political machinery of the Republican party is geared towards driving animosity and fear regarding the existence, and perceived incursion, of melanated populations in order to make their targeted base population leave their houses and vote their fears. As this GOP noise machine hums along, our national conversation also slowly devolves into stupidity and anger.