Also, I wonder how can the Democratic party can still be credible in denouncing Republicans efforts to suppress voters the right to vote when employing the exact same tactics during the primaries.
I looked up one of the referenced incidents -- the botched poll in Arizona -- and based on other articles (see: https://www.washingtonpost.com/news/the-fix/wp/2016/03/31/ar...) it's hard to tell from a bird's eye perspective whether even that was "rigged".. or whether it was mere "incompetence".
I know FiveThirtyEight, referenced several times in the paper, (http://fivethirtyeight.com/features/the-system-isnt-rigged-a...) lean against the "rigged" argument, which is where I stand from a big picture perspective. Political shenanigans always happen, but regardless of this, demographics explain the result of the Democratic primary more than anything else. (That being said, in my opinion, the same demographics should frankly tell the Democratic Party to handle the Sanders supporters much better than they have been so far.)
It's as though the comment is trying to prevent overracting, however weigh it against the threat of underreacting. The harm in taking these allegations too seriously (false positive) is doing research and finding out the statistics are invalid (extra research time). The harm in taking these allegations not-seriously-enough (false negative) is mass-scale election fraud.
Given how hard it is for such allegations to even be considered at all in our social climate (even when we all know they're much more technically feasible than people would like to admit) I think a defusing this article detracts from pursuit of truth in exchange for peace of mind.
So let me bring up some exhaustively prepared articles from the past. A lot of these are from the late 2000s when the "voter ID" issue was in play, but I do not think the electoral landscape has changed that much since then.
A report on voter fraud in 2007 from the Brennan Center concluded a very low rate of voter fraud in 2004. http://www.brennancenter.org/sites/default/files/legacy/The%...
News21 (part of the Carnegie Knight media initiative) created a database of voter fraud. They found little. http://votingrights.news21.com/article/election-fraud/
We have this Washington Post reporter who tracked voter fraud, and found little. https://www.washingtonpost.com/news/wonk/wp/2014/08/06/a-com...
And... another paper on how "voter fraud is in the eye of the beholder." (Harvard Law Review) http://www.harvardlawreview.org/wp-content/uploads/pdfs/anso...
So... that's a lot of data (I could link many more reports from this era) that indicates that, frankly, voter fraud from any angle really hasn't been a big issue before (and that any perception may be due to political bias, perhaps). I do believe there's plenty of inefficiencies regarding the American electoral process, and that might be right ("inaccurate, costly, and inefficient" as the Pew Center on the States alleged in 2012, that I buy -- http://www.pewtrusts.org/~/media/legacy/uploadedfiles/pcs_as...). But there's a difference between incompetence and awful systems, and outright fraud.
I must acknowledge that this isn't the only paper alleging fraud in the 2016 primaries (https://drive.google.com/file/d/0B6mLpCEIGEYGYl9RZWFRcmpsZk0...). I will note however that, for this one, Snopes was skeptical in that the numbers had not been peer reviewed by independent parties (http://www.snopes.com/stanford-study-proves-election-fraud-t...) and note counter-viewpoints ala Joshua Holland of The Nation (who does not think much of "exit poll conspiracies": https://www.thenation.com/article/reminder-exit-poll-conspir...)
This is why I'm very cautious. Bias is huge in politics; it may be exhaustively prepared, but if they are using bunk statistics, it's not worth much.
It's okay to take back something you said in error in HN, you don't always have to double-down.
If it's not clear, I'm not saying that the paper is wrong per se.
There are ongoing lawsuits relating to this where many people of varied interests are going to be pouring over this, and other data, way more than I can at the moment.
If the results of the lawsuits validate this paper, then this paper is important.
But it's also possible that the lawsuits will not be successful.
Historically most claims of voter fraud have been wildly exaggerated, which is why I bring up the past. Including the fact that bias unfortunately colored many fraud claims in the past.
Maybe it's different this time. Maybe not. We'll see.