My previous post
dealt with an incident in which something a politician said was used by her critics as evidence of historical ignorance. In that particular case, for reasons I discussed, they were wrong—what she said did not imply what they claimed and if it had the implication would have been more nearly true than they realized.
But I am sure there are many other cases where a politician says something in public that really is strikingly wrong in one respect or another. Having read transcripts of my own speeches, I do not take that as much evidence against the speaker. In an unscripted context, it is quite easy to say things you don't mean—for instance to leave out the word "not," thus reversing the meaning of a sentence, or to change what you are saying in mid-sentence, with the result that the transcript shows the first half of one sentence followed by the second half of a different one.
What politicians say, however, mostly reaches the ears of voters through the media. That makes possible selective filtering. If you like the speaker, don't report the literal absurdity, on the reasonable enough grounds that he obviously didn't mean it. If you don't like the speaker, do report it, on the grounds that he is enough of an idiot so that he probably did mean it. The voters then conclude that the politicians whom the media they watch or read approve of are much more intelligent and reasonable than ones they disapprove of, whether or not it is true. Where the major media have fairly homogeneous beliefs—Sarah Palin is an obvious example—the result is that most people regard the disliked politicians as stupider and nuttier than they are. The exceptions are mostly the partisans on the other side; nowadays they can get the opposite filtering from blogs and web sites that share their bias, in the past from magazines that did.
As it happens, I know the opinion of two prominent past politicians held by someone who had had considerable first hand interaction with both. His view was that Barry Goldwater was an intelligent man although not an exceptionally intelligent one, and that Teddy Kennedy had a below-average IQ. That is not the view of the two men that one would have gotten from the media back when they were active politicians.