The way I see it, this graph boils down to four things:

1. Perceived level of understanding is a dangerous thing. But then, we knew this.
2. Self-identifying independents of 1993 were largely moderates. Today, they are (apparently) the far right that finds the GOP not-quite-lunatic-enough and (probably) some fraction of former GOPers who are horrified by that party today. A “voted-X in last election” cross-tab would’ve helped here. A lot.
3. The epistemic loop seems entirely responsible for the shift in initial wrong-ness, and misperception among Democrats that also has to be corrected through painstakingly slow re-education and gradual convincing. Lots of Democrats were buying into the Death Panels horse-shit too, after all, they heard it on the news, so the news-givers must be making at least a casual effort at factual correctness instead of merely reporting what various “sides” said. Right? Right? It is a mortal lock that these Democrats are older, and came of age with Walter Cronkite. They implicitly trust what they hear on TV, even if it’s on FOXnews. You can (eventually) convince them otherwise, but only with a lot of work; and research shows they still marginally believe the wrong fact if it comes first, even when said people realize the initial fact is misinformation. This is why primacy in the race to inoculation in the messaging war matters so goddamned much, and yet the Democrat categorically refuses to use it.
   Nearly 80% of Republicans self-identifying as “not knowing much” about healthcare reform knew that there were going to be Death Panels. More than 80% who “knew a lot” thought that as well. This is FOXnews, Rush, Beck, and Drudge (aka the MSM’s assignment editor). No other explanation for it.
4. The Facts Do Not Matter

Full report (PDF link) here.