The underreported part of the DNC email scandal is that it occurred, apparently, because Russian operatives hacked the DNCs. Clinton campaign chair Robby Mook said that "...experts are telling us that Russian state actors broke into the DNC, stole these e-mails and other experts are now saying that Russians are releasing these e-mails for the purpose of helping Donald Trump.”
In this election cycle, the Democrats and Republicans were each beset by someone from outside the party who wanted to be president. Bernie Sanders, a long time independent senator, and Donald Trump, an unaligned nut job, joined the Democratic and Republican parties, respectively, the year they entered the primaries.
The Republicans, despite knowing how dangerous Trump is, allowed him to become the candidate. Leading Democrats apparently discussed over email how to keep Sanders from winning the candidacy (even though he was always a long shot). Of course they did. And so they should have.