Well, it's certainly not the only thing we are to measure. I've advocated that it's but one quality of voter discernment among many others...namely, voting record, present position statements & rampant inconsistency of past position statements, social issues' stances, character, viability, scandal-free past, etc.
But I vehemently disagree the way you've dumped this into the category of only blaming Mitt's parents & grandparents & great-grandparents. At some point, adults assume responsibilities for their own worldviews -- including other-worldly worldviews...ESPECIALLY when they are giving 10% of their MILLIONS to inject it into cultures all over the world!
And, since we are talking about Mitt Romney (as well as Huntsman), may I reinforce Mitt's "True-believing" Mormon status:
I recommend this interview with author Tricia Erickson to all: Tricia Erickson: 'An indoctrinated Mormon should never be elected as President'
Erickson mentions that: Mitt…held…offices of…Missionary, Missionary Zone Leader, assistant to…Mission President…,…Bishop and Stake President…You cannot attain the “calling”…to serve as Mormon Bishop or Stake President unless you are a thoroughly entrenched and obedient Mormon…
Erickson's book now out is entitled: "Can Mitt Romney Serve Two Masters? The Mormon Church Versus The Office Of The Presidency of the United States of America."
The Constitution of the United States of America, Article 6, paragraph 3: "The senators and representatives beforementioned, and the members of the state legislatures, and all executive and judicial officers, both of the United States and of the several States, shall be bound by oath or affirmation, to support this constitution; but no religious test shall ever be required as a qualification to any office or public trust under the United States.
I have already stated that I do think that Romney will be the Republican nominee for President because of his views on "manmade global warming", which I am convinced is a hoax that has an anti-freedom agenda behind it. His being deceived on this point is a valid reason for not supporting his bid for the presidency.
You are free to publicly oppose Romney because of his religion. You are free to try to amend the Constitution so that a religious test becomes required, so that any person born into a Mormon family, unless they repudiate that religion, are forever banned from holding any office or public trust under the United States. If that is your desire, go for it. I would not recommend it, because many people might view the endeavor as divisive and hate-filled.