Caller ID is just the number. They leave no message.
I call back after hours (using *67 to block my number). I hear a recorded message. Their message is a decent quality computer generated (female) voice. I hear the following, "Thank you for calling. We apologize for the inconvenience of the call you received. Our organization was created by a group of devoted conservatives who wanted a way to effectively support candidates by motivating like minded voters at the grass roots level. Our goal is to organize, motivate, and mobilize the conservative voters of America to help elect and support candidates who share our same goals and values. We are dedicated to replacing the Obama administration with strong conservatives willing to make the difficult decisions necessary to steer our country in the right direction both fiscally and socially. We believe deeply in the preservation of a system that protects our liberties while supporting our rights. Press 1 to hang up, or press 2 if you wish to have your number removed from our calling lists. Thank you." (I press nothing as it can actually make things worse.)
I received a similar call from another number on another day. During the day they gave their name as something like "Association for Homeless and Disabled Veterans". A few minutes later it was the "Veterans Action Network". If you can't get your name right, I know you're a SCAMMER. Their night time message was the same as above. My research shows that they are all likely scammers who do not give anything to veterans.