Taking all the necessary steps so that one exact candidate (Trump) won't win the next election is "undermining democracy" already, especially as those steps now come from both business (Twitter, FB) and the media (Washington Post, NYTimes).

Maybe the Democrats and the people who are called "liberals" don't realise it just yet, but they've lost the game because they've started playing Trump's game. Like I said, they might technically win it this time around, but the next "Trump" will probably be younger and even more charismatic, and he (or maybe a she, why not?) will have to conquer a public scene which will have already known by that point that the democracy rules don't exist for either party, so why care for the democratic process anymore?

If it matters I'm not from the US, have never set foot there, just saying how I see things from half a world away.