Why Is The Tariff Issue Controversial?

Setting aside that it could depend on the size of the tariff and the product involved, if you stick to one proposal at a time why is there such a debate about each one of them? If you put a 50% tariff on widgets from Babylon it would seem to result in obvious results. Yet there is this big debate, Are people disagreeing about what the results would be or are they disagreeing not about the results. but rather about whether we want those results?