there are lots of concrete ways that this manifests itself. one example is drug prices.
it is apparently now common practice to import generics from canada, which is actually completely insane if you understand how the system works. drug prices in the united states are ridiculous, granted. but, canada is actually the second most expensive oecd country, and it is largely the consequence of the american market.
the united states has essentially no meaningful regulation on drug prices, which is completely absurd.
in canada, what we do is take the oecd average. so, if you want to buy a drug in canada, the price is calculated by adding up the prices in all of the other oecd countries and then dividing it by the number of countries. if you have a situation where the drug is 100x more expensive in the united states - a random if round number, but hardly an absurd exaggeration - then this dramatically skews the average, which actually inflates the price.
for america to try and fix this by importing canadian drugs is to provide a very minor discount on a problem of their own making. if they would simply regulate their industry, prices would come down on both sides of the border.
so, if sanders wins and brings in pharmacare, canadian drug prices will come down dramatically. who can say we don't have an interest in this?