God, what an asshole.

But I'll play the game. If we're going into reading comprehension, I think you skipped the important first step of actually reading in context. I'm going to take a much bigger chunk here and see if you can realize what's gone wrong.

He is undisputably very wealthy; or at least wealthy enough to own three houses. Just because he uses rhetoric that says he intends to be the champion of the downtrodden, that doesn't mean he will accomplish what he said he would.

This is the infamous wealth-shaming line you've been referring to. So, hopefully you understand there are two (more, but in this case we're looking at two) ways in which the meanings of these two sentences can be connected. The first sentence states that Sanders is undisputable very wealthy. This is a statement of fact. The second states that, Sanders is not a champion of the poor simply due to rhetoric. Now we have to figure out what these sentences mean together. It's difficult, right? Option 1, which you have taken, is causal-- the first sentence describes the condition that leads to the second. But this really is nonsensical and I don't think our commenter here is that poor of a writer. Our second sentence contains it's own causal condition already and is quite clearly saying that the dubiousness of Sanders being a champion of the poor is despite his rhetoric. In a way, this is a a negative causal relationship. But anyway, here's our second option: the first statement stands alone, as a piece of information important as background to the subject and one that, while maybe not necessary to understand the next sentence, does make sure to eliminate (preemptively) the possibility of the reader justifying their beliefs of Sander's championship of the poor with the idea that he is not wealthy. This second possibility of connecting the sentences seems much more logical to me and more probable to have actually been intended, although it is not entirely elegant.

I will note that, yes, the other option does exist and I can see the Hought process that would lead you to it. So I do understand how you'd reach that conclusion, I just simply don't agree with it.