Bernie Sanders has been a fucking Washington insider for the last three decades.
This idea that Sanders is some outsider who is immune to right wing smear is devoid of any reality and the fact you so willingly fall for right wing smears against Clinton to try and prove your point that Sanders' is immune, just proves the point even more that some folks are really out of touch with reality.
You say "how would you take down someone like Sanders using a bad faith attack machine", ignoring what the entire concept of "bad faith" is! You are contradicting yourself two sentences into your own post about how Sanders is smear proof using logic that is self contradicting.
Saying shit like "he fights with conviction" is just stupid. It's stupid because it brings this idea that nobody else does, that nobody gives a fuck and he's somehow in all of politics the only person who is capable of saving the human race in some majestic, inhuman way. He fight's with "conviction" because apparently, repeating the same thing for thirty years is what people find inspiring. Nah fuck getting shit done, fuck actually doing politics where you have to inherently compromise when you're dealing with 60 votes (within your own party across two branches of legislature), that shit is WEAK.
Real conviction is having the same stump speech over and over again, where you get to point at a video from 20 years ago and say "See! I have conviction because I'm just saying the same thing", because when ever the conversation is brought up that's literally all anyone ever does.
I'm sorry to burst your bubble, but Sanders is not some magical person that's going to inspire a generation. He didn't do it in 2016, he didn't do it in 2018, and nothing is showing he's doing it now. He's not some underdog that is up against the machine. He's not losing because it's him vs. the world and the world is doing everything to keep him down, no matter how much people keep repeating that same tired bullshit.
Bernie Sanders is DC. Bernie Sanders is politics. Bernie Sanders is not above the bullshit. Bernie Sanders, when the chips are on the table, takes the money and does what any person representing their state does. He has a record of doing it even when it's shit like the Military Industrial Complex, or gun control. It's why people get fucking tired of hearing Sanders as some holy symbol that if criticized simply "doesn't care about working class people", because it's all reductionary bullshit about class warfare.