Did you notice the difference in vibrancy between the Obama brochure and the Clinton brochure? When you're designing your campaign brochure, it is especially important to capture the attention of your potential reader. But, you also need to balance this need with the need to stay within your budget. Thus, the very first thing you will need to do when it comes to the design of your brochure is determine: Will I use color, how much color will I use, what printing technique is available to me, and what kind of paper will I print on?
It is much less expensive to print in black and white, or even high quality black and white than it is to print in color. If you keep the color on your brochure limited to only a few places, you might also be able to keep the cost down if you're using a standard printing press method of creating the physical brochure. Finally, high-quality heavier stock paper will be more expensive than a lighter weight paper. You might be better-off purchasing regular paper and folding it than you would buying pre-folded brochure paper.
In the media gallery, I have uploaded a template for creating your political campaigning brochure. In both this template (meant for use with Scribus, a freeware program for creating professional-looking desktop publishing projects), and in the image just above to the right, you'll notice that there hasn't been much use of images while the brochure used for Obama's campaign made heavy use of images, but only used a little bit of text.
What you do with your text to image ratio will be important. I suggest you have no more than one image per brochure section. Otherwise what will happen is your reader will lose track of the purpose of your brochure—that is, to convey information—and it could create distrust in the candidate. You'll notice that in the template, there is space for captions for the images. While you don't have to use captions, it can be a great way to get in a few one-liners like "Candidate x values education" or "Candidate x had an approval rating of yz%."
Once again, make absolutely sure that any images you use are high resolution. Otherwise, you run the risk of having blurred or indistinguishable images when the brochure prints. Believe it or not, this is even more important if you're printing in grayscale.