Mormons and Christians

A reader writes:

I'm sure I won't be the only one to correct you on this, but Romney is a Christian by any meaningful definition of the word. All Mormons are Christians.  Christ is unquestionably the central figure of the faith; in fact, the official name of the church is "The Church of Jesus Christ of Latter-Day Saints."  Some other Christians have decided that because Mormons have a different view of the Trinity, spend a lot of time talking about church founder Joseph Smith, and believe that each person has the potential for godhood, they are not Christians. Ask any Mormon if he or she is a Christian and they will say yes. Who gets to decide this important question: Mormons themselves who profess a profound belief in Christ or exclusionary Christianists who want to denigrate the faith of others?

I say this as an atheist ex-Mormon who really doesn't give two cents about the underlying theology, but it still bothers me every time I see this trope coming from some quarters that Mormons aren't Christians which apparently gets picked up and passed on without a second thought.  And it's something people need to get right as I'm sure it will be discussed ad nauseam once Romney's campaign gathers steam.

I take the reader's point. But Muslims also revere Jesus. And the inspiration for Mormonism's radically innovative understanding of the message and life of Jesus - Joseph Smith's "discovery" - is so alien to mainstream Christianity (and so transparently loopy) that I don't consider Mormons Christians. This is not to say I don't support their religious freedom or their right to play a full part of American politics and society. But they're not Christians as I understand Christianity.