NationBuilder (organizing, fund raising, canvassing, elections)
With the elections coming in 2016, you may want to look at NationBuilder sooner rather than later.
Including 190M voters (free), NationBuilder appears to be a one stop shop for organizing, fund raising, canvassing, etc.
You could build your own system, but the time and resources spent will not be furthering your cause.
Disclaimer: I have not used NationBuilder nor do I have any relationship, financial or otherwise with NationBuilder.