Local blogging Republican Bob Krumm upbraids Evangelicals for not accepting Mormons under the GOP umbrella as they have Catholics (he fails to mention that Catholics are not a monolithic voting block and they swing both Democrat and Republican; but that's a debate for another day).
It is fairly clear to me that our local Republican blogger does not understand Evangelical culture, even within GOP. It took a century of Catholics accommodating to Americanism (Evangelicals have historically been anti-immigration and nativist; Catholic Church growth in America has tended to rely on immigrants, but has also tended to promote accommodation in order to survive) and the lightning rod issue of abortion for Protestant Evangelicals to feel comfortable working along side them. Evangelical theological issues with Papal Authority pale in comparison to the perceived heretical, sectarian anathema that the Latter Day Saints are to Evangelicals (plus, LDS’s missionary zeal and huge growth are real threats to the imperial spirit of Evangelicalism).
It should be perfectly clear to those of us who are not saddled by partisan wishful thinking why Evangelicals would not vote for a Mormon candidate (Mitt Romney). Begging "common cause" assumes that both sides see a cause in common. Evangelicals don't.
UPDATE: I would draw your attention to the comment section where Rob refers to the theological dimensions of the cross that cause the wedge between Evangelicals and Mormons. I would argue that both conservative and liberal partisans trivialize those theological dimensions for their own strategic purposes in the sense that Stephen L. Carter (The Culture of Disbelief: How American Law and Politics Trivialize Religious Devotion) uses when he calls such treatment reducing religion to "an unimportant facet of human personality, one easily discarded, and one with which public- spirited citizens would not bother." In this case, I think that Bob Krumm glossed over Evangelical theology in a way that trivialized its reaction to Mormon theology.