I don't think that it's uncommon nor that there are specific ideological groups that are particularly willing to be lied to so long as they're told what they wanna hear.
That said, Socialists seem to gulp down the Kool-Aid with particular alacrity.
You have to have spent very little free time learning about world history to not know about the Holodomor. Maybe you can be forgiven for not knowing that the Soviets managed to keep most of the world ignorant of the genocide for several years. Perhaps you can be forgiven for not knowing that The New York Times was complicit in the cover-up. Maybe you still don't know how or why the cover-up happened. Well, it's because people like Walter Duranty figured that looking the other way, not asking questions, and only reporting what the government wanted him to was a small price to pay to have all the drugs, alcohol, and hookers that he could handle. In the meantime, journalists like Gareth Jones had the lives of their friends and family threatened if they dared to report anything negative.
This wasn't an isolated incident. These dictatorships have always had a habit of being restrictive about who they let in or out and for how long. When the Soviets let Rexford Tugwell explore their grand experiment, they showed him the high life and wined and dined and entertained him to the point that he didn't think to ask about the well-being of the average Soviet citizen.
When the powers that were in East Germany wanted to downplay the shocking spikes in suicides, they just stopped keeping track of suicides and decreed that suicides should be recorded as "self-murders."
This lasted to the end of the Soviet Union. Bernie Sanders made his pilgrimage in the 1980s and was treated like royalty. He was shown the best hospitals in the Soviet Union and was convinced that it was like that everywhere. Though, in the few cases that they did let Western doctors in to help with overflows of patients, the Western doctors were so appalled by the hospitals that the average person went to that they thought the patients would be better off taking their chances at home.
Of course, useful idiots like Michael Moore have always been willing to advertise for the dictatorships. Moore did the same thing when he made Sicko and showcased the hospitals that the government cronies got to go to. He kept his cameras away from the rat infested hell holes that average Cubans go to. He conveniently left out that the people are so poor that doctors moonlight as cab drivers.
After more than a century of blatant lies from every Socialist dictatorship that's existed, we're still living in a world where, when Castro died, major media outlets decided to praise the Cuban literacy rates and life expectancy. We still have people who look at Venezuela through rose colored glasses. It seems like a lot of these people, who just take Cuba's reports on life expectancy as gospel, have never thought that maybe, just maybe, they're lying to us.
Somehow, it seems like most Americans are consistently willing to entertain the possibility that our government is cooking the books to make itself look good; but, for a lot of people, it doesn't occur to them that brutal dictatorships would lie to the world.
North Korea has managed to get to the point that even the most devoted Western Socialist can see the lies. In order to believe that Kim Jong-un always hits holes in ones and never poops, you pretty much have to be indoctrinated with that from the cradle. Still, Western Socialists buy into similar rhetoric to the North Korean dictatorship. They might not buy the lie that North Koreans are told about South Korea not being a complete hell hole because they steal from North Korea; but, Western Socialists regularly blame the economic strife of Venezuela on Western Capitalism's interference. So, they don't buy Kim Jong-un's lies; but, they eat up the lies of Hugo Chavez and now Nicolás Maduro.
Yeah, to an extent, I get it. If Right-wing dictatorships were as common now or in recent years as they were in the 30s and 40s, you'd see the same thing coming from the other side more often. It's not unusual for human beings to want societies to organize around their own views of the world.
Socialism sounds good to the kid who just got out of a liberal arts college with $70,000 of debt and no skills. When it sounds good and you want it to happen, you're willing to believe the lies that are being told to you by the people who are telling you that they'll fix your problems.
Still, it takes a special mind to see the massive trend of lies and still think that this time they're telling the truth.