In any type of business-to-consumer calling you're going to need to hire a lawyer before you even design the system because of all the telemarketing regulations (at federal, state and local levels) that have to be followed. There's lots of documentation to be prepared that you have to make available to anyone that asks while you call them, there are rules about how predictive dialers can be used (such as maximum drop call rates and dead air times), etc.
Politicians, when writing these telemarketing regulations, purposely wrote clauses into them excluding political calls. Ya know, consumers don't want to be bothered by telemarketing so our politicians actually listen and pass these laws, but it's OK for them to bother us with telemarketing still.