The dictionary describes white space as "the unprinted area of a piece of printing, as of a poster or newspaper page, or of a portion of a piece of printing, as of an advertisement; blank space."
Commercial ads get this and use it effectively quite often.
Political ads and mail on the other hand seem to think that if there is more space you should just add more policy and issue bullet points. Because everyone is interested in your 27 point plan to reshape local government right? Not so much...
My point is instead of trying to make your next piece a "issue summary" why not pick one issue and use high impact visuals and compelling, but concise, copy to deliver a message that leaves an impression on a voter.
Do not believe that continuing to decrease your font size is the best way to squeeze in more text. Resist the urge to turn your mailing into a white paper on policy. Use your mail to push an interested reader to you web site. Your campaign site is that place where you can have the 27 point plan with 15 part appendix.
Last but not least please please please skip the stars, elephants and eagles that so many political candidates seem to think are mandatory. If your mailing says "Smith for Senate" then voters don't need a gratuitously huge flag and a elephant shooting stars from it's trunk...they get it, you are running for office.
Good luck and feel free to post your examples of really bad/good mail pieces to our facebook page for Fans of Political Mail .