On US blogs I keep seeing the word rube appear.

As here:

For all the talk of Sarah Palin being a rube, just a backward waif from Wasilla, Alaska, few seem to appreciate that she, more than any other rumored 2012 Republican nominee, has mastered the cutting edge art of e-Campaigning simply by being herself and employing the very latest in e-Tech to great effect…

Or here:

I find this type of rube manipulation by the GOP to be highly irresponsible. Sure, this type of hype will fool the highly emotional rubes into voting Republican, but it will also incite some of these stupid and excitable idiots into killing people.

The nomenclature issue even briefly divides Instapundit and Ann Althouse:

UPDATE: Ann Althouse responds. I wasn’t calling her a rube, particularly — the "who are the rubes?" line has been a running thing with Obama, going back to this post: "When it comes to things like NAFTA, there seem to be only two possibilities. Either Obama’s anti-NAFTA talk is a ruse to fool the rubes, or his coterie of distinguished economic experts is a ruse to fool a different batch of rubes."

To expand a bit: Either the people who believed the early-primary left-talk are the rubes, or the people who believe Obama now are the rubes . . . or anyone who thinks Obama has fixed principles at all is a rube. Your call.

ANOTHER UPDATE: From one of Ann’s commenters:

I think the meaning of "rube" is similar to a hustler’s mark — someone who believes things they shouldn’t because of some externally generated desire to believe. There’s an element of conscious deception, too — a rube is lied to, not misled.

I think the rube factor with Obama comes into play on two issues in particular: NAFTA and the war. On both issues, you get the impression that he’s making promises that he not only won’t keep, but that he can’t keep and shouldn’t keep.

As defined by online dictionaries, the word means an awkward unsophisticated country person (related words include bumpkin, chawbacon, hayseed, hick, yahoo) or more generally a naive/inexperienced person. But that reader definition as above is notably more subtle:

… someone who believes things they shouldn’t because of some externally generated desire to believe. There’s an element of conscious deception, too — a rube is lied to, not misled

In Serbia back in the 1980s petrol stations were manned by people who pumped petrol into your car. One easy trick was not to flick back the counter on the pump, so that if (say) the previous car had had 20 lires and you ordered 40 litres, they would pump in only 20 litres until the pump showed 40, then charge you for 40. A banal winner if you did not check the pump before they started.

The Serbian slang for someone who fell for that one was pecurka – mushroom.

Here’s a treat from a time-machine: