That's what the bottom line if for you??? If Romney (as most Mormons) considers himself a Christian and you don't you'd vote against him on that basis???
First of all, it's not the only consideration.
Like others in here, I weigh issues like personal character, social issues' stances, voting record, public statements.
Secondly, I've already said that even among the faith issues, the "definition of true Christianity" is not the only issue. The Bible shows that it's important for leaders to be guided by God, and to persistently call upon Him for guidance (the prayer issue we've talked about). Also, as I've mentioned, pinpointing a candidate's discernment skills are very important.
Let me give you a parallel: We don't want to be solo issue voters, right? So we don't want to evaluate a candidate on the solo issue of abortion, right? Well, yes and no. "No" in that many other issues and character and track record and faith issues all also come into play. But "yes" in that a person's commitment or lack thereof toward the most vulnerable in society will tell you a lot about the rest of what I just mentioned without even looking. A pro-abortion candidate will usually have a libertyless voting record. If mayhem in the womb is a non-issue to him/her, or if he's/she's pro-violence in the womb, then what does that say about his/her character?
Also, as I pointed out in my previous post, the definition of true Christianity is not something that occurs in a vacuum. And neither does properly "reading" Islam. Properly reading Islam, and its elements, IS a vital foreign policy/national security issue! If a president doesn't get a proper "read" of the threat posed by some elements of Islam, then where is his/her natural security discernment? (I mean don't we call it a gaff if a candidate makes an off-base comment about some world religion?)
So what? You think discernment skills in the Oval Office is a kindergarten issue? You think it doesn't matter if a president is wildly off-base in his/her understanding of Jihadic Islam, or of other world religions like historic Christianity? These are simple take it or leave it issues?
If you think that, you are naive. We can perhaps "get away with" (to some degree) such outright deception at lower offices, but not in the Oval Office in this juncture of our history.