Title text:
"You legs may have a comparative advantage at running, but we arms have a competitive advantage at swinging hammers, so unless you accept that we're the dominant limbs and stop hogging the oxygen, that running advantage won't be around for long."
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3290/
There are other cases to be made. There are things of stretegic importance you want produced domestically. Trump complains about Canada having tariffs on dairy. Obviously he mischaracterizes it, but there are indeed limitations of the amount of food Canada imports from the US.
We don't want to become dependent on the US for food. Because we don't trust the US. For obvious reasons.