That said....down south, I doubt I would be considered Christian enough. My mom cannot wrap her head around it that I believe in Jesus, celebrate Christian holidays and baptize my kids. I am Orthodox for crying out loud. Its not like I fell off the edge of the world. They are not just assuming you are Christian by a a generally accepted moderate definition but that you are Western Protestant Evangelical Christian who believes exactly what they do about politics . So even a large chunk of Christians are subject to a) the visible shock and horror of finding out that someone is not an EveProt Christian (because if you are in the south and are Catholic or Orthodox you might as well be a Satanist) b) attempts to save us.
I think it may be at least partly a denominational and/or regional thing. I get the same kind of reaction as Lilyka sometimes, and not from Roman Catholics, who are the largest Christian denomination around here, but from "EveProt" Christians. Some have been told I am "Christian" or "traditional Christian" and immediately made assumptions about my politics and family life. There seem to be a certain number of Christians who think of Christianity not as a doctrine but as a kind of lifestyle package deal.