You're right about voting in midterms but you're wrong about these things not disproportionately affecting Bernie. I will bet gold that if the results are changed by this revelation it will be to Bernie's benefit, maybe not in delegates, but at least in the popular vote. 126,000 voters, geographically in chunks of entire city blocks (not definitively, but potentially areas where Bernie's ground game had knocked on a lot of doors) were removed from Brooklyn's Democrat voter rolls, and NY admits that they don't even have an explanation for 70,000 of them. This is Bernie's hometown and the borough he was expected to perform best in, and it matters. Bernie won a vast majority of counties but lost in all the boroughs and barely in Buffalo, and these consolidated geographical location resulted in a significant delegate deficit because they are so populous. AZ I actually did a substantial amount of research on back when I though anyone would give a shit if I made a blog, and the jist of it is that the geographically largest county in the country which is also the most populous county in AZ, containing 9 out of 10 of the state's largest cities, removed polling locations in a pattern that appears to deliberately have targeted low income areas, and it was so egregious that the DOJ is looking into it and both campaigns have sued. To put this in perspective, there were 400 locations in '08, 200 in '12 because there was only a Republican primary, but there were 60 in '16 , which is a 71% decrease from '12 in a year with twice as many eligible parties voting. /u/kybarnet is right about big cities, although I would chalk up the "invisible supporters" talk to be Hillary's campaign having a strong strategy of getting absentee ballots out, most notably to nursing homes which are a favorable demographic to her. Seeing as some of her mailers are inaccurate sample ballots that don't recognize Bernie Sanders as an option of what candidates you can vote for, there's a possibility these old folks are being misled (this is called "granny farming" in the UK and it is illegal there) but I really don't put much stock in that excuse. The only case where a city probably would have been favorable to Sanders in a battleground state was Phoenix, AZ because it is a majority minority city and Bernie does better with Hispanics than Hillary, yet there was only 1 polling place for the entire city on the day of the primary. Irregularities should be investigated in all states, and maybe Hillary supporters are just less prudent, but it appears to only be happening in states that Bernie has lost. I guess we will find out as this story unfolds, but if there appears to be a repeated effort to systematically disenfranchise supporters of a certain candidate or political leaning, I would hardly write it off as incessant whining.