Did you ever see a movie called "Kidco"? It was about some kids that started a business selling horse manure. The state bureaucrats got involved and tried to shut the kids business down. It went to court.
The kids called their father as a witness. (It was his horse farm where the kids got the manure.) The Kid, acting as his own attorney, asked his father if he paid taxes on the feed he gave the horses. His father said yes, and presented receipts showing the payment of taxes on the horse feed.
The Kid then informed the court that taxes had already been paid on the product when it entered the horse, and the state was trying to tax what was expelled from the horse.
"Your Honor! The State is trying to tax both ends of the horse!"
So I think you get the idea of how trade works. They don't send us goods unless we send them goods. A tax on imports is a tax on exports. It's the same products going into one end of the horse as is coming out.
