John Fund asks Romney about giving “the speech” and about what Rep. Bob Inglis is reported to have said to him, “You cannot equate Mormonism with Christianity; you cannot say, ‘I am a Christian just like you.'”

“I don’t recall the conversation so precisely that I can describe my exact reaction to that.”
Recall precisely. My exact reaction. Sometimes one forgets that Romney was trained as a lawyer, but not on that day. I tried one more time. “Well, okay, if you have been told that by other people, what is your reaction to the substance of what they are saying?”
“You know, the term ‘Christian’ means different things to different people,” Romney told me…

I don’t think it’s such a great idea to relativize the faith of others, especially a group that you are specifically targeting. It tends to make them cranky. Romney really needs to reconsider Inglis’ advice, this is an area in which he might want to flip-flop which shouldn’t be a big deal given that his flipped on most of his positions already.
BTW, defining Christianity isn’t very hard, the church has laid it out in two very handy little creeds, the Apostles’ Creed and the Nicene Creed which have been the confession of the church throughout most of its history.