Its not a double negative. It is saying that a petition right now is worthless. Pure and simple.
Your only hope is to show that the mayor commited a crime by destroying the field. Your absolute only hope. Cause then, to reconcile, you may get funding to rebuild the strip and guarantee the field's survival for a little while longer.
Basically, if the action was legal, you are not deciding on closing a functional strip, you're deciding on what to do with a nonfunctioning one.
MiniD