Putting aside the "what makes Trump supporters so special" questions what really needs to accompany automation the most is educational reforms and funding - the work is condensed and more complex by definition but effectively means superhuman capabilities per person. That will be the future just as basic high school was needed for more factory work when the apprenticeship model broke down for many tasks and the roles were specialized and transient.
Another good use of the surplus labor less ammenable to retraining is infrastructural upgrades that aren't as readily automatable.
I also wonder about automation proliferation - when it will start to appear more at small business scale or if scaling will keep things centralized more.