The argument against tariffs is based on the idea of comparative advantage, which is extremely hard to argue with. There are people who bring up legitimate criticisms around the edges, but the core idea is solid, and would have been just as valid in the 19th century as it is today. The idea of strong protective tariffs is fringe today because relatively more people understand the economics of trade.
Unfortunately, relatively few people, even today, understand the economics of money.
Gold is a fringe idea now – and rightly so – but the argument against gold in history is not so good, especially as you go further back in time. There was a time when precious metals served as a good anchor, and the economic system was, most of the time, well-served by that anchor. Fiat currency was difficult because no one had figured out a way to make it work consistently. However, things changed as time went on. Money became more and more based on underlying trust rather than actual possession of a heavy, hard-to-transport metal. Eventually people became so accustomed to working with money as an idea, as a ledger entry in a book rather than as a heavy object in a vault, that the metal backing was holding things back instead of helping us out. At that point, it was time to let go of the golden fetters. Recovery from the Great Depression began in earnest only after the gold peg was dropped. That last vestiges were removed in the 1970s, and gold is simply silly today. There is no help it can provide anymore because going back to it would require trust that we would stick with the system, but our current system is already based on the same kind of trust. Going back to gold doesn’t offer any extra backup of trust anymore.
The “free silver” debate in the late 19th century was a reaction against the deflation of the time. Deflation hurts debtors. You borrow 100 dollars, and you have to pay the debt back with 100 dollars that are worth more – that is, 100 dollars that are harder to get – than the original money you borrowed. Plus, there’s the interest payments on top of that. The populist movement of the time wanted silver because they wanted more money, more inflation, which would ease the burden of their debts. If a transition to silver had been done not long after the Civil War, it might’ve worked fairly well. But by the time the Free Silver movement really got its steam, silver was worth comparatively much less than gold and the inflation from going back to the old 16:1 ratio would’ve been intolerably high.
That doesn’t have a lot of direct translation to today, except in the sense that sometimes more money is good and sometimes less money is good. The 1970s? Too much money. Now? Too little, like in the late 19th century panics. In today’s situation, we have a big problematic private debt overhang. If money were to move more quickly – if the total value of the dollars that changed hands every year were to return closer to its previous trend line – then economic recovery would be much more swift. Money can both cause, and ease, economic downturns. It’s a strange thing.