I think it is simply the US shale oil production is mostly light sweet and pushing out imports of the same.
Refineries that were upgraded to take heavy, sour oil still run most economically on heavy sour.
The biggest drop in crude oil imports is from light sweet.
I am much more interested in Arab Opec oil, and would hope that the combination of US, Mexican, Brazilian, Venezuelan and Canadian oil would bust wide open OPEC cartel.
Also, I want us off Arab oil, so the terrorists have no beef with the USA since we won’t need to use troops to keep open access to Arab oil.
How many Americans have to die and be wounded for people who hate us enough to call us the great Satan, and send terrorists half way around the world to kill us.
Plus, for as long as OPEC has been around we have been paying Mafia type prices for our oil