I like Dan Gutman's writing because it's funny, and has a nice flow to it. This book is no exception, but it can be challenging keeping up with all the political details. It's a good resource for learning a little about how elections work, but you also may want to check out Dan's book Landslide (see below) for more specific information about U.S. elections.
Read The Kid Who Ran For President if you like stories about kids who dare to try difficult things (kind of like Andrew Clements' stories), interesting realistic fiction, or books that keep you guessing until the end. For a hint of how the book ends, keep your eyes open for the sequel, and the title may give you a clue.