"Off of" is an appropriate colloquialism.
Check it out.
But, yes, I'm right. In fact, I have far better chance of being right than you. One of my choices is ANY conservative with an 80% or higher ACU rating.
I win because I've got lots of leeway. Simple math.
Your numbers shrink fast when another requirement is put in: that more that 10% of the electorate have HEARD of the potential candidate.