"On July 22, 2016, WikiLeaks released online tens of thousands of messages leaked from the e-mail accounts of seven key DNC staff. Some e-mails showed two DNC staffers discussing the possibility that Sanders' possible atheism might harm him in a general election with religious voters. Others showed a few staffers had expressed personal preferences that Clinton should become the nominee, suggesting that the party's leadership had worked to undermine Bernie Sanders' presidential campaign." --Wikipedia entry.
The supposed secret plot by the DNC to influence voters
The thinking of disgruntled Sanders supporters (happily touted by Trump and Russian bots) is that the Democratic National Committee, without doing anything overt to affect the primary election, surreptitiously influenced voters to vote for Hillary Clinton. Hillary won the popular vote over Sanders in the primaries 55.20% to his 43.14%. In a general presidential election, percentages like that would be landslide territory. According to the unhappy-Sanders-voters-Trump-Russian theory, if it were not for Wikileaks, the public would not be aware of the influence that the DNC had over voters which caused the majority of voters to vote for Hillary in the Democratic primaries.
Wikileaks "exposed" the political biases DNC staffers
Newsflash: People who work in politics have political opinions which they discuss in private emails among themselves. Farmers discuss their opinions on crops and agriculture. Doctors discuss their opinions on diseases and medicine.
It's hard enough to influence voters with public campaigning
How is it possible that private emails between DNC staffers had any influence on voters? Many are concerned that unlimited money in politics buys advertising which has an out-sized impact on our elections. Now we are supposed to believe that private emails which cost no money, unfairly influenced a large majority of voters in the Democratic primaries.
If the DNC had a magic formula to influence voters...
why didn't they employ this secret sauce in the general election?
If you can respond to any of the questions and issue raised here, there is probably a job as a political strategist you should apply for.