When Millennials start voting in large numbers, what they want will be listened to by politicians. So far, many of them don't vote, so, so far, they are paid lip service by most politicians, but in reality, largely ignored; ignored more by republican than democrat politicians, but ignored nevertheless. Bernard Sander's hitched his campaign wagon to a bunch of non-registered non-voters; hence his failure. In the interim, between our two plutocracies, roughly the period between women's suffrage up to Citizens United, if you wanted to be successful in politics you'd find out who is actually going to vote, and then tell them what they wanted to hear. Nowadays you find out who has the money to support politics and tell them what they want to hear. Of course there will never be enough people with money to elect anyone, so the politician still has to find out who is going to vote and cow tow to them. In the meantime, the people with the money hire all the best marketers and video producers. Once you get to Washington it's those with the money that count.
Millennials don't fit into either of these schemes. Most likely, unless by miracle the Democrats can take the Senate, and then pull off a second miracle by legislating around Citizens or getting it reversed, the nation will move inexorably toward total plutocratic fascism. You'll still get to vote in federal elections, but it will be even more meaningless than it is now. This will return the nation to a "more perfect union" as envisioned by its founders. The nations approximately three-quarter-century experiment with partial democracy at the federal level will be seen by historians as an interesting interlude. We will return to our roots, as a plutocratic Republic with the best government money can buy. And who is to say that democracy or plutocracy is better, Winston Churchill not withstanding? All forms of government are defective, but in different ways. Plutocrats favor, well, a plutocracy, whereas the rest of us look favorably on a more democratic government. And good luck with that!
What might be interesting is the question of whether democrats decided not to work because they are democrats, or whether those not working decided to be democrats because they weren't working? 
