Tariffs help prevent foreign manufacturers from flooding a countries markets with cheap products that the countries manufacturers can not compete with and still maintain a healthy profit margin to be able to keep a business running and the need for employees. Here is a page to explain it more in detail. Www.wisegeek.com/what-is-a-tariff.htm
They do not protect Jobs nor Wages they keep jobs from being made. Everyone wins from free trade, this issue was settled decades ago.