American labor unions support trade barriers because they

Tariffs encourage domestic trade, and keep jobs in America. if a country like China pays their workers next to nothing, they can sell their goods for considerably less than an American company, which has to pay higher wages, for healthcare, vacations, etc.

he agreed with Churchill in wanting to invade the edge of the German empire (controlled by Hitler), wanted to give the army experience, and wanted to help Britain protect the Suez Canal

Explanation:

While the majority of American military leaders had their doubts about the value of a North African invasion and its chances of success, President Roosevelt was attracted to the idea largely because it afforded an early opportunity to carry the war to the Germans.