Matthew Yglesias takes a break from all that substantive policy stuff about how bad George Bush is to talk about Star Wars a bit, complaining here and here that since the films pretty clearly establish that about twenty years or so pass between the end of Episode III and the beginning of Episode IV, it seems odd that the Jedi will have gone from well-known throughout the Galaxy to not-very-well-known-at-all.
Matthew is, of course, wrong.
The Jedi aren't unknown by the time A New Hope dawns. They're unknown, basically, to one character only: Luke Skywalker, and it's not hard to see why. He's grown up on a very distant planet, that is established in the Prequels -- even during the Republic's hey-day, when the Jedi are still in vogue -- as not being particularly "up" on the great internal affairs of the Republic. Remember how Qui Gon Jinn tries to apply some Jedi-based muscle on Watto, and how Watto blows him off without too much concern that he's about to be vivisected-by-lightsaber?
This reaction by Watto seems to indicate that the Jedi, even in the time of the Prequels, aren't exactly held in reverence by the Galaxy-at-large. The Hutts are also established (in Return of the Jedi) as not giving a shit one way or the other about the Jedi, to the point of being immune to the Force-driven "mind tricks". Han Solo refers to the Jedi as a "hokey religion", but he's a Corellian pirate (a group of people who can't have terribly long lifespans), and who also very likely never much held the Jedi in particularly high esteem either.
The people didn't forget the Jedi; they simply never much cared about them in the first place, at least as far as the Prequels go, and it's also worth noting that Matthew makes a fairly common error that Steven Den Beste also once made: the Jedi at the time of the Prequels have already been in decline for many, many years, and the situation in the Republic has been growing more and more difficult and precarious. To read the Star Wars chronology as implying that the Jedi are magnificent warrior-priests up until a certain event X, after which they are barely remembered, is simply wrong, to say nothing of Matthew's evident belief that not only have the Jedi been supplanted, or even forgotten, but by the time of Episodes IV, V and VI, they are supposed by many to have never existed at all.
Matthew also makes an odd assertion that there is "no indication in Episodes IV-VI that Anakin's turn to the dark side was coincidental with the fall of the Republic and Palpatine's assumption of the office of Emperor". Well, I guess there isn't, since you don't have Ben Kenobi saying specifically something along the lines of "Now, all this stuff I'm talking about happened roughly at the same time", but it's never once occured to me to suppose that the fall of the Jedi (which Ben clearly indicates in A New Hope happened partly because of Vader's actions) didn't happen at the same time that the Republic fell, since numerous other threads of discussion in the film imply precisely this. Example: "For over a thousand generations the Jedi Knights were the guardians of peace and justice in the Old Republic, before the dark times, before the Empire" (emphasis added). Or the fact that as Episode IV transpires, the Emperor has only now got round to ditching the Senate. And so on. This assertion is simply baffling.
Finally, Matthew says this: "What's more, Obi-Wan specifically says of Anakin in the original 'I thought I could train him as well as Yoda. I was wrong.' This is not a very good description of the events portrayed in Episodes I and II." Well, no, it's not, because all of Anakin's training takes place in the ten-year period that elapses between Episodes I and II. But basically, Qui Gon insists on training Anakin, and Yoda says, "Bad idea"; then Qui Gon dies, and Obi Wan steps up and insists on training Anakin, to which Yoda says, "Still a bad idea, but we'll give it a shot". And as Episode I ends, Obi Wan has only just become a full-fledged Jedi Knight, and not by undergoing the traditional Trials but rather for his efforts in the Battle of Naboo. So here's the newest member of the Jedi Order, insisting on being handed what the Council believes to be the most problematic Force-sensitive person they've ever found. In light of that, Obi Wan's rueful remembrance in Episode VI seems pretty accurate.
But of course, since it's apparently to be taken as a given that George Lucas is a colossal pinhead who has only managed to blunder into two good Star Wars films by some bizarre miracle, I'm clearly fighting a losing battle here. Kind of like the Jedi in Episode III.