The discussion of the broad political lack of appeal of minority religions or absence of religion is perfectly factual and perfectly sensible. Many of us, me included, have raised the issues here about polls showing how politically reviled atheists are as indicative of the general animus against us in public. That a political operative who should be far more involved and far better informed than casual commentators like us knows the same facts is not outrageous at all. It would be outrageous if he didn't know and discuss it.
It's offputting to some degree that he implied making use of it, sure. But in reading the emails I'm not sure how much was musing and how much was planning. We can certainly all agree that no plans were put in action to capitalize on his purported atheism.
What we should find outrageous is that it still is possible to attack someone by calling them an atheist, or to lesser extent politically at least, Jewish or Mormon or Islamic. If we were the country our Constitution claims us to be, this would be no more possible than attacking them for being left handed. That's where the outrage should be, far more than about people knowing atheists are reviled, and more even than leveraging that revulsion, as it was against Pete Stark to very little outcry by the way. It is the fact that the revulsion exists that should bother us.
Some here make that same irrational leap and confuse the real problem when any even vaguely savvy observer noted how easy it would be to paint Sanders as a far left Socialist/Communist. It is not "hippy punching" to be aware of how negatively perceived those words are and how easily they can be applied, using his own words and deeds, to Sanders. It is simply awareness. I find European style Democratic Socialism to be nigh universally positive. I even find real 60s style British Socialism to be positive when judiciously applied, to such things as utilities or transportation (but Christ never consumer or B2B manufacturing). There are even certain things about Communism, in theory at least albeit not seen in practice at a national level, which are positive. But I'd be a blithering idiot if I didn't realize the electoral vulnerability of those labels. We shouldn't complain that atheism is known as a potential electoral weapon either, or be all that worried if it's used as one. The challenge is stopping it actually being so.