What if... We had not shut the door on the immigration wave in 1921?

[Psychic Octopus]

?

[Matt Damon™]

We close it in 1929.

[mianfei]

We close it in 1929.

Most likely that would have happened, at least if there was a major depression as actually occurred.

I was just thinking that the black civil rights movement might well have been handicapped from not closing immigration, since the Eastern European immigrants were even more racist that the French or the English tended to be. Moreover, it is an unpalatable but true fact that black civil rights has progressed best when immigration has been lowest. This was true not only during the 1950#, but also in the early 1800s when Mark Thornton showed a quarter of a century ago that the free black population grew by 180 percent during a period of extremely low immigration (which Thornton fails to note as such), yet ceased  during a period of immigration increasing.

[True Federalist (진정한 연방 주의자)]

There would have been at minimum a much less pronounced Great Migration north of African Americans. After all, why would northern employers want to hire cheap, easily exploited blacks if they could still hire cheap, easily exploited whites in the form of newly arrived immigrants?

Incidentally, Eastern European immigrant racism in the late 19th and early 20th centuries was in part due to the same causes as Irish immigrant racism in the mid 19th century: economics. "They'll take our jobs" is hardly anything new to the Trump-era.

[Skill and Chance]

Assuming the door remains as "open" as it was in the 1910's straight through to the present day, Dem dominance is even more dramatic during 1932-68 than it actually was.  It's entirely possible that the GOP never recovers from the 1930's and gets explicitly replaced by something like Europe's Christian Democrats by 1945, but either way, the right's platform would move much faster and more decisively in that direction.  In 1968, a conservative running on Nixon's platform would have been much stronger, probably 2 landslide wins in a row and they flip congress at some point during that.

I am really not sure how it would impact the elections between 1976-2000 if they occurred between the same 2 candidates.  More likely, the Reagan-Bush and Clinton-Gore political movements just never happen because their coalitions simply wouldn't be large enough to compete.  The fiscal conservative push may simply never happen and we just go straight from Nixonism to Trumpism, with wealthy suburbs and tech workers ending up in the Dem coalition much sooner and Republicans holding onto Nixon's gains in the industrial North and making it their base. 

Society would be less socially liberal in general.  I doubt Roe v. Wade and Obergefell would have happened, but some states would have legalized abortion and gay marriage on their own. 

[darklordoftech]

I wonder what the effects of more Jewish immigration would be.