The Vote for Pedro Font
The font used by Napoleon to make his "Vote for Pedro" t shirt is a font from the Cooper family of fonts, namely Cooper Black. Other fonts in the Cooper family might work just fine, but I have found that the Cooper Blackfont approximates the font used in the movie pretty much exactly. You can check out the prints on this Metro Manila site which used the Cooper Black font and see for yourself what I'm trying to say.
Chances are good that you already have the font installed on your computer. To test and see if you have it just look at the text sample below:
If you can see the font the way it's supposed to look that means you have the font! If you see it as just a regular Times Roman font, then you don't have it installed on your computer.
I'm not sure where exactly to get the font for free, but you can probably find it available for download somewhere from a fonts site.