[When imported industrial goods are immediately thrown into the void]

I have already proved that free trade is totally incompatible with nationalism, national sovereignty, and the future survival of the nation due to the labor mobility required by it. Now I will prove that even complete autarky would, in the present circumstances, be of material benefit to the United States economy.

First, what passes for the macroeconomic facts, courtesy of the BEA:

Q4 2017 GDP was $19,386.2 billion.
Net exports were $2,420.7 billion
Net imports were $3,020.8 billion

Now, let us accept the free trade advocates' standard argumentum ad absurdum and suppose that Donald Trump actually does shut down all international trade going forward. Let us suppose that China, Japan, and the EU all retaliate with 100-percent tariffs and refuse to sell into the world's most profitable consumer market. What does this mean in statistical terms?

It means the US economy loses $2.4 trillion in exports and gains $3.0 trillion in imports. Remember, GDP is calculated by the following formula: C+I+G+(x-m). So, this much-feared trade war, at its theoretical worst, would result in the instantaneous growth of the US economy from $19,386.2 billion to $19,986.3 billion GDP.

That is three percent annual growth, which is faster economic growth than the USA has enjoyed since the 1990s. In other words, the very worst scenario that the free traders can envision actually guarantees a bigger and better economy growing faster than the USA has seen for more than 20 years. And given the fact that US manufacturing prices are more expensive, the actual GDP growth will probably be in excess of that.