Your efforts are not wasted. The antics amuse me mostly because I live among the same type of people, and that this area, like yours, suffers from a dearth of Bush/Cheney signs (all the ones set out tend to be found destroyed the next day).
If fireworks were legal in this state, I would recommend attaching some sort of hidden 'howler' (perhaps at the bottom of the post hole?) attached to the post of the sign with a rip-cord/string. It might not awake/alert you, but it'd sure surprise some guy in the midst of wiping Gorilla Glue all over himself.
