The “if U.S. and Russian borders were only 100 miles apart” item reminded me of a very interesting article draft that I once saw, which began,
The patent clerk is not known for his genius.
I suspect this is generally quite true, and the counterexample that will come to many people’s minds — a patent clerk whose very name is now synonymous with “genius” — is just an entirely unrepresentative accident. (In a similar though not identical vein, the fact that part of the U.S. is indeed less than 100 miles away from part of Russia doesn’t much undermine the substantive claims made in the article in which the quote appeared.) Still, if the counterexample instantly comes to many readers’ minds, it will distract them and weaken the article’s force even if — after some thought — the readers will realize that the counterexample doesn’t really undermine the broader point.