Don Miller's post is interesting, but too vague to understand if it is his opinion or not. Pyromaniacs has an interesting take on his post in the form of an open letter.
However, I thought the most provocative post was written by Orson Scott Card. He is a Mormon and also an excellent author. I finally got around to reading Ender's Game last year and it is a great book, one of the best I have read in my limited library of science fiction. His post is below:
7. Mormons have delivered the vote for Republicans year after year, but the GOP would be wise to remember that Mormons don't actually belong to them. We noticed and will not forget Mike Huckabee's viciously anti-Mormon mockery of Mitt Romney during the 2008 campaign. If Huckabee is the Republican nominee for president, look for substantial numbers of Mormons to defect or abstain. Mormons are the key to Republican victory in many Western swing states; if Huckabee actually wants their votes, he'd better start mending fences now.
–Orson Scott Card, Mormon author whose books include "Pathfinder"
After a quick internet search, the only thing I came up with was that Huckabee made the statement that Mormon's believe Jesus and Satan are brothers in 2007. Huckabee has since apologized to Romney face to face and to the public in general. While Mormons and Christians may seem to share some beliefs, the reality is that key differences in Orthrodox Christianity and Mormonism should often lead these groups to vote differently.
It will be interesting to see how Christians vote in the next election. It seems that the best Republican choice for President is Mitt Romney, a Mormon, and that the loudest (prophetic?) Conservative voice these days is Glenn Beck. Should Christians vote the traditional party line? Or are there real differences between Christianity and Mormonism that deserve closer examination?