This "fact check" of Bernie Sanders' newsletter on Biden and Social Security is just flat out wrong in multiple ways, and I'll explain how politifact.com/truth-o-meter/…
Politifact says Biden was being sarcastic and mocking Paul Ryan when he agreed that you have to cut Social Security to balance the budget. But that whisper thing Biden does is an old move: he does it when he's speaking forbidden, politically incorrect truths to the left 
Go watch Biden speeches, you'll find that whisper move is consistent. Means he's attacking the left. But ok, say you don't believe me. It's wrong on a second count here. Politifact bolded the wrong words. The right ones are highlighted ("it still needs adjustment"):
"Adjustment," in Washington, is a euphemism for "cuts." That's just a basic fact of congressional lingo that can't be disputed, but I don't blame Politifact for not being familiar with it. Now that they are, this should be corrected.
This part, though, there's no excuse for. They used as their neutral arbiter a guy from an organization founded for the purpose of cutting Social Security in order to cut the deficit. Background on them here: huffpost.com/entry/peter-pe…
Also this last part is just a minor correction, but it's not true that Sanders said this. It was in a newsletter that actually says the views are those of the author solely.
The context is also important: Biden has been in favor of cutting — freezing, adjusting, whatever you want to call it — since the 1980s
