Another idea is to simply transmit an attitude or idea about the issue without necessarily mentioning the issue itself. This could work if you're thinking along the line, as you suggested, of a series of stickers that have a similar and identifiable look. Something like:
Stiffen Up, America!
or, with frustration...
Fer Chrissake, Stiffen Up!
Of course that particular message might be misinterpreted, in various ways, but you get the idea.
