I do the same; though not 'professionally'; but graphology an earlier past-time of mine. I would say; without question; these two signatures belong to. . .two different people.
Let's see McAulliffe's signature or maybe Begalia. . .Carville; or would they get some poor Dem-shlep to do the job; someone with nothing and everything; to lose.
Somebody surely must be asking CBS; WHO the expert is; that made this determination. . .
I think Brit Hume is going to discuss this.