"Μολών Λaβέ"
“Moving box” refers to the ability to move to another state within the USA if the policies & laws of that state are not agreeable and you can’t affect satisfactory change.
This is one of the primary reasons the left implements all of their policies at the federal level - instinctively, they want to control you, so allowing you to move to another state to avoid that control is abhorrent to them.