while attempting to push a wire line and pvc to the skimmer in an effort to free the plug we found that we were hitting something hard where we thought the plug was. I think it must have been a "T" or something. maybe where it "T"s to the drain. Who the hell knows.
Anyway, we knew it wasn't rubber. SO we had already cut the line and thought perhaps the plug was between the cut and the pump. We stuck fish tap (heavy wire) in the pipe and attempted to guide it towards the pump.
It only went a few inches. We quickly cut another section and found the plug.
TOTAL LUCK. Because when your skimmer sucks something in..how the heck are you supposed to know where it is in the line?? Luckily it was where we were able to dig and super close to the first cut. I can't imagine it being wedged in the pipe under the cool deck.
I swear I will never use one of those compression plugs again. The wingnut was plastic btw and I think it failed.

Thanks for all of the ideas!
Carl D- you were so right, Cut it out! We're just lucky enough that we didn't have to cut the deck.

Now on to the other problems...