"The new Gallup poll, conducted June 9-12, finds nearly 20% of Republicans and independents saying they would not support a Mormon for president. That is slightly lower than the 27% of Democrats saying the same."
This is the line that I find surprising and which cast doubt on the validity of the poll. Given the stats about how republicans are more religious than democrats, I would have expected a higher percent of republicans to have an issue with Mormonism than democrats.
You’re not counting the fact that, I think, almost all Mormons are Republicans. Utah is the second most conservative state according to a recent Gallup poll.