I’m guessing the best route is to use the ambiguity of “left” as noun, verb, and adjective. When you think of the main argumentative use of the word, to describe a wing of politics, it may get easier. Maybe start with the mnemonic for which side of a boat is “port”:
The boat left port.
Now substitute some argumentative words for the nautical ones, and have a little fun. I’ll be glad to see what you come up with, or to do a quick online lesson to talk it through.