Bright side of the current reaction. The decline of the European powers was bolstered by the land grab that was the USA – basically the oppression of indigenous and slave Americans was invested in a temporary world domination culminating in the Marshall Plan and Marilyn (the famous Monroe doctrine of coca-colonisation). But the only America that can be made great again by incompetent boorish land speculator Trump will be his accidental spurring of central and south America towards cross border action. Take a longer view and recognise how the anti-colonial triumphs of the 20th Century will, no doubt in convoluted ways, deliver on the promise of the massive transformations (Russia, China etc) of populations and aspirations for justice in the 21st. The centre is real old and the periphery is on the up, dialectics is not just propaganda but recognition of patterns and analysis of historical shifts. Migration changes the world for the better, and claims to any other outcome are myopic idealism, racist self-harm and stalling of the inevitable.
(On inadvertently hearing The Donald on the radio).