Keep the Jones Act (Merchant Marine Act 1920) in its current written state. It also affects national security.

https://www.google.com/search?q=Jones+Act&oq=Jones+Act&aqs=chrome..69i57...
This act has been in effect since 1920. It protects our Mariners, local jobs across the country that contribute to ship repairs, and national security. It ensures that only US boats transport goods and people at our ports and borders; including rail and air transportation. If McClain succeeds it would be another opening for terrorists to enter the country and will send many of our jobs out of the country. We stop this now! McCain has stated he will press for changes until it happens, it's time we push back!