Consider your closest family and friends from back home (read - outside of DC): How many of them vote in primary elections? How many really understand how a bill becomes law? Do they know the difference between a PAC and Super PAC? Or comprehend the way interest groups shape the legislation that governs our lives? I bet many of them do not, because they are not involved in these things day in and day out like we are. What we must keep in mind is that our audiences - those we are asking to "take action" or encouraging to vote, or asking for a PAC contribution - are no different than your family and friends.
In order to effectively engage your employees or members, you need to go back to the basics and start with education. While we may have paid close attention in our U.S. Government classes (because we wanted to absorb as much knowledge about such an intriguing subject as possible), many others may not have been quite as interested back then. They didn't understand the importance of involvement in the political process at that stage in their lives. Now, you have a chance to take advantage of what are, hopefully, more interested and open minds, by giving them information about voting, the PAC or issues that affect them.
Many people truly do not understand how the political process affects them or why their involvement matters, but we often assume everyone gets it, just because we do. You will be much more likely to get people to write or call their legislator if they understand that their elected official has a say about a piece of legislation that could affect their jobs or industry. Many do not know how close some of these votes can be and how essential their opinions are to legislators. There are many employees who do not fully comprehend the way the election process works nor how critical primary elections are, especially this year. And PACs are incredibly misunderstood by so many - there is no way you will get people to give up their hard-earned, personal money to something they don't understand or view negatively.
I strongly encourage you to think of your general audience in a new light - they likely don't know as much as you think they do, but they are ready and eager to learn. BIPAC's Market Research Report shows that employers are the most credible source for information, beating political parties, the media, and labor unions. Respondents reported that their awareness of, and involvement in, the political process increased after receiving information from their employer. Also, don't fall into the trap of thinking they don't want to have you cluttering their inbox - 80% of employees are either satisfied with the amount of information they receive or would like to receive more.
In this day and age, people want and need concise, pertinent, trustworthy information, and you are able to provide that because of the credibility of the employer. While some in your audience may already know and understand a lot more than the basics, you have a large segment who would be not only receptive to, but also appreciative of an education in how and why the political process matters to them. So, go back to the basics and remember to educate your audience - the level of engagement (and in the case of the PAC, receipts) is almost certain to increase.