"You don't think the question mark makes the point that it's an issue of contention in the article?"
No, the question mark is not enough. As I said, when you would say it to someone, you could ask the question in a way to make it clear that you mean "Why should Christians bother to vote for Dems?".
But when you just read it as a stand alone, the question mark implies that you ask the question of why Christians SHOULD vote for Dems and you will give answers.
I really think it's better to make your major point right in the title, with the addition of the NOT.
In your e-mails, if you haven't sent them yet, I would even make it a statement: "Why Christians should not vote for Democrats". Remember, a lot of people really don't get much past the title, and this way you get the message to those too, then people can read the body of the message to understand your reasons.
I appreciate your feedback and will definitely consider it. I haven't sent the email yet. Maybe I should put an action line in there near the end about getting priests, pastors and bishops to educate their flocks...
But on the flip side, the whole point of your email is to influence those Christians that are already inclined to vote for Democrats to vote Republican. I think it would be more likely that they would actually read the email if they initially thought you were giving reasons to validate their choice.
Furthermore, this email is full of information sources that Christians that vote Republican might not be aware of and it could be useful to them. We get so much email that we have to make choices in our limited time as to what we will read and not read. I personally would not have read this post if you had titled it "Why Should Christians NOT Vote for Democrats?" I would have just thought, "DUH!" and moved on, but your title made me want to come see what idiotic reasons there could be and I gained some valuable info in the process.