In a two-party Us and Them political world, the incentives are there to moan. The other side is stupid or evil. With big Nation-based Welfare States, there is also a conflict between the idea of who the 'contributors' are, and who the 'recipients' are. In a global system where much of your success is determined by the lottery of the passport you win at birth - there is bound to be (at least some) selective migration. Come if you are a recipient. Leave if you are an unwilling contributor.
(Enforced) Fairness v (Voluntary) Justice
In a world of abundance, we are in a better position to do what we believe is right voluntarily. Imagine a country that is torn between two political parties - one believing in a 10% tax rate (Tithe), and one believing in a 50% (Share) tax rate. If the Tithe Party win, there is absolutely nothing (in a Liberal Democracy) stopping the Share Party pooling the 40% extra. Nothing except the feeling that *EVERYONE* should contribute. We don't have to change anybody's mind in a world where there are enough willing people. Politics can shift to being about seeing people, rather than convincing people.
Abstract Redistribution v Community Building
Big states are abstract. Our prejudices tend to be abstract too. If you have only ever had bad experiences with a certain 'category' of person, prejudices are bound to be soaked into you. Even unconsciously. That is how people learn - through repetition. The only way we break that is with real relationships. The homophobic religious parents whose son gets married to a man. The best friend who marries someone of a different race. The new colleague or boss who is really good at their job. We need to get better at having our communities based on real relationships. Communities with names, faces, and stories. Communities that see alive people.