Here is the remarkable reporting by Lawrence O'Donnell on the 2016 election

[Maineman]

25. BUT, there would have to be enough Democrats willing to do what needs to be done.

There would need to be enough Democrats who focus on real needs rather than trying to compromise with the radical right.

There would need to be enough Democrats with backbone to stand against the media war the Republicans, corporate profiteers, and big money greedy jerks would wage.

A Democratic president would need to be a real Democrat, not someone with debts to corporations, and friends and allegiances to big money.

It would need to be a president with great skill at leading and informing the uninformed masses.

There is a lot more to be done than just electing persons with a D beside their name. It is entirely possible that the right wing strategists have a multi-pronged approach including infiltrating the Democratic party.

Other right wing strategies obviously include running 3rd party candidates to split the vote, messing with the Electoral College, discouraging voting, psychological warfare to discourage voters, dirty tricks, lies, misinformation, on-and-on it goes.