The change is so slight that it is not statistically significant.
True but the scary thing is the that Ryan never really got a good bounce that most VP’s get when announced. That COULD be a problem.
I wonder if part of that was that it was at a different time than it normally comes. Usually the VP announcement is a day or two before the convention begins, so it may be hard to net out convention bounce from VP bounce. At any rate, both Romney and Ryan need to show themselves very well at the convention, especially Romney who is still sort of a cipher to the public, I think.