Trump's proposal to raise Tariffs and reduce income tax, is what we had prior to 1913. Ron Paul often said, we had no income tax prior to 1913. But he doesn't say that in its place we had gigantic trade tariffs with Europe. The income tax was first introduced in a bill as part of a compromise over tariffs. back then our tariffs were effectively a regressive tax on consumption, and this tax very badly felt. The income tax was a progressive tax in it's place. Today of course it's regressive, hitting middle income earners hardest. But it has to be. No country ever taxed the wealthiest of its earners, the majority of private income, at 40%, and expected to collect it all.
Tariff is very interesting geo-politically. I don't know much about it. The european Union was originally the european economic free trade area, in the 60's, that was the pressing issue, it wasn't a political Union. But now the British want to secede from it. The British steel industry being crushed by imported Chinese steel. I don't think it's inconceivable to see a return of the tariff in major world economies... But Trump's proposal of 30% tariff on Chinese imports is pure populism, like his Mexico plan. Some kind of tariff might be welcome though. If it's accompanied by income tax reduction.