ACH/WI: The US never imposes any immigration quotas?

[iddt3]

So this might be a bit pre 1900, with the Chinese Exclusion Act and all, but what if the US never imposed any serious quotas on immigration? Let's say that the CEA gets dropped sometime in the early 1900s, and for whatever reasons (No red scare, no WWI, strong immigrant lobbies, well timed political distractions) Congress never gets around to imposing quotas. What circumstances could make this happen, and what would the effect be? If it's not plausible in the modern era, what's the latest the US could allow more or less unrestricted mass immigration?

 

[Viriato]

You're going to get far more temporary migrants, or "birds of passage" that were coming from Southern and Eastern Europe. These were mostly single men who made the voyage to the Americas with the specific goal of earning enough money to buy land back home. These were over a third of all immigrants during the 1900-1913 period, and were overwhelmingly single males. The good thing about this was during periods of economic contraction many simply left home or went to other countries such as Argentina. With increasingly inexpensive fares, this will only increase. This also will help the economies of Italy and the Balkans.

Jewish immigrants will continue to immigrate in larger numbers so that by the 1930s Poland and Romania's Jewish populations will be a lot smaller. The vast majority settled in New York City and its environs. Without the restrictions, New York City is far more Jewish and a little less Italian. Although there were Italian communities, many Italians did not put down roots until the restrictions made Italian men afraid to leave, and many have relatives come join them. As a result, many will remain labourers and there will be fewer Italian businesses overall.

 

[iddt3]

Interesting, so seasonal economic migrants remain much more viable, while there are more political migrants as well. Does more international labor mobility help alleviate downturns and tamp down on anti immigrant sentiment? Do more political (presumably mostly left wing) refugees mean a more radicalized electorate nationally?