Now that your sign has been vandalized, it owes you nothing. Any life you can breathe back into it is like reincarnation.
I am with the booby trappers. Non washable dye should do it..
Put up a tiny secret camera - probably a neighbor who could use some social media presence.
This has happened to me quite often when I put up pro Democratic signs or anti GOP. It’s because right wingers are nazis who don’t respect private property rights unless it’s their private property. I think you should move the sign so it’s visible from the house, put motion detector and camera up to catch culprit. If they vandalized your sign, no telling what’s next.
PS, I have had bumper stickers that got crazy ranting letters left under my windshield wiper. I have never felt the need to reciprocate as it’s a waste of time and writing utensils.