&quot;Gay marriage is an obvious one, (Australian) treatment of refugees, anything else?&quot;<p>I&#x27;m pretty sure gay marriage will be seen as just as normal and wholesome in 50 years as it is today or even more so. Though there will be fewer gay people if the theory that homosexuality is genetic proves out unless we have a boom in surrogacy.<p>The German and EU treatment of supposed refugees will be seen as a tragic moment, probably. Australia&#x27;s current policy will be the one that any rich liberal nations that persist in being rich and liberal in fifty years will have chosen. Look at the UN population projections. It&#x27;s clear that indiscriminate migration will overwhelm nations with lower than sustainable birth rates. Those that import many millions of people from backwards nations with extra high birth rates will see their founding populations reduced to tiny minorities and their countries newly backwards.<p>Prohibition is the obvious choice.