It's funny that Ultra doesn't just respond to me directly, and that he feels the need to impugn my motives rather than just make his point.
Anyway, the idea that anyone thinks that Bernie has been smeared at all (much less is in the midst of an "unprecedented smear campaign"!) IMO shows just how unprepared his followers are for what's to come if he wins the primary. Hillary had about two-thirds approval when the smear campaign started against her, and to this day, people (not just extreme righties) are convinced that her highly rated charity was some kind of corrupt front, that she regularly has political opponents murdered (murdered!), that she ran a child sex-trafficking ring, and generally that she was some kind of corrupt monster. A plurality of Republicans believed that Obama was not born in America and that there was a long-running conspiracy to suggest otherwise, a quarter of them thought that he was the Anti-Christ (that's not just me exaggerating how much he was hated--that's people who would tell pollsters that they believed he was the Anti-Christ), and 70% thought he was a socialist. And Bernie will be much, much easier to characterize that way. He genuinely does have a lot of unpopular positions, and there are scandals and attack avenues that have never been brought up because of the need for his primary opponents to play nice.
One Berniebot here said that Warren's representation of his (likely accurate) claim that a woman would have a harder time winning as "a woman can't win" was the most despicable campaign smear he'd ever seen or something to that effect. What's going to happen when the real war starts? I'll tell you now that I think a lot of people who are currently backing Bernie will ditch him (note that a lot of those people claimed to like Warren before she surged in the polls and started getting attacked).
But, yeah, Republicans wanted to sow discord on the left in 2016 and their approach was to say lots of nice things about Bernie and promote the CT that he was screwed. Conversely, Clinton's campaign didn't want to sow discord on their own side in 2016 so they also played nice with Bernie. It was an extremely clean primary, and he didn't get attacked by the other side. This time, it's similar. But if it goes to the wire in the primary or if Bernie wins the primary and faces a general, it's going to get turned way, way up. And he's not starting from a place of high popularity like other primary winners were (see my point about Clinton being at ~65% when she started getting smeared).