I'm gonna say something possibly rude about the Bush family.
Verbal ability varies, and maybe it is inherited. We know that George Herbert Walker Bush [mouthful there!] had trouble with language sometimes. I used to put it down to his being a guy, a warrior athlete and not a verbal thinker, women being usually more voluble than men.
BUT the Bushes had one son, Neil, who is definitely learning-disabled. I call Neil the Best of the Bushes, because despite his involvement in the Denver savings and loan scandals he was perhaps more patsy than perp, and has since become an entrepeneur in technology for the learning-disabled.
We all know about George Walker Bush. Smart enough guy but more trouble with language than his dad had. I remember back in late '06 I think it was, he gave a press conference relating to Iraq where he was often incoherent; sounded like he was drunk, but it was apparently just inability to put thughts into words and string them together grammatically.
You may remember Dubya at that press conference referring to without naming the Iraq Body Count,
www.iraqbodycount.org/, which at that time showed maybe 35,000 Iraqi civilians killed [5 times that now!]. He was obviously emotionally disturbed by the dead in Iraq [but that Johns Hopkins survey around that time calculated a half million dead in consequence of the invasion, so at 35k Dubya's conscience was getting off real easy].
I thought Jebulon [what I call Jeb, no idea if that's his birth name] had escaped the family disability, but now it looks like he hasn't. He is slow verbally and not quick at spontaneous thought and language, which puts him at a disadvantage in debates. I blame genetics.