I fundamentally agree with all this. Scandinavian style social democracy has been the apple of my eye since I first graduated high school straight into the War on Terra.

My concern (which I hesitate to fully express, lest my Hispanic ass be labeled a “white supremacist”) is that Euro-style social democracy is incapable of surviving waves of economic migration unseen on the continent for literal millennia.

Either the right wing is correct and the migration itself will be overburdening the social structure to the point where it collapses - or the right wing is wrong about full collapse, but the stress fractures from mass migration are enough to put the Prophets of Privatization in power and make it a self-fulfilling prophecy.

Indeed. Immigration is the big test for European social democracy, though I'd argue that so long as the social contract is respected, and economic rewards are evenly and justly distributed, then we should be ok. If people have good jobs, affordable housing, and a future for their children then they are much more amenable to accommodating outsiders. Unfortunately this is not how things are working out right now - Europe has been badly affected by wealth concentration (driven by zero interest rates? Offshoring? Financial engineering?) just as the US. For example in Portugal house prices and rents have exploded in recent years, and who are they blaming? Digital Nomads, when in fact AirBnB is facilitating lucrative short term lets for those (often Portuguese) landlords able to take advantage.

Note that some places in Europe have already seen large scale immigration since WW2, usually from their former colonies - e.g. UK, France, and Portugal again.

The same arguments were made 100 years ago that the Irish, Italians and Chinese would never assimilate in the US. I was in Paris recently and saw multiple groups of young people of mixed races hanging out as friends. I asked around and confirmed that yes this is a new positive development in the last decade or so.

Kids don't care about race or ethnicity. It just takes a generation or two.