Bernie Sanders. (Michael Reynolds/European Pressphoto Agency)

Bernie Sanders isn't too happy these days with the party he ran to lead in 2016. And he wants to make sure you know it.

In a lengthy — and very good — New York Times Magazine piece on the future of the Democratic Party, Sanders was asked what the party stands for. Here's his response:

You’re asking a good question, and I can’t give you a definitive answer. Certainly there are some people in the Democratic Party who want to maintain the status quo. They would rather go down with the Titanic so long as they have first-class seats.

That's remarkable. Not only did Sanders run for president in 2016 — and win almost two dozen states! — but he also is now a member of the Democratic Senate leadership thanks to Minority Leader Charles E. Schumer. And, when asked one of the simplest questions in all of politics — what does your party stand for — he admits he can't really answer it.

Part of that is simply for effect. Of course Sanders can offer his own vision — a liberal one — of what the Democratic Party stands for and where it needs to go. He chooses not to because he views the party as still too in thrall of the power brokers, donors and consultant class and not committed enough to real change. By saying you don't really know what the party stands for, you are making sure people know you're not happy.

If you need to understand the roots of Sanders's annoyance, look no further than the just-concluded Democratic National Committee chairman's race.

Sanders was an early and active backer of Minnesota Rep. Keith Ellison's bid, believing that Ellison was committed to a bottom-up approach to party building that represented real change after the devastation of the 2016 election. Ellison began the race as a clear favorite, but establishment Democrats — including former president Barack Obama — helped urge former labor secretary Tom Perez into the contest.

Former labor secretary Thomas Perez narrowly defeated Rep. Keith Ellison (D-Minn.) for chair of the Democratic National Committee following a contentious battle over the fate of their party. Ellison called on his supporters to rally behind the new chairman. (Alice Li/The Washington Post)

Perez beat Ellison rather easily on a second ballot, proving that the establishment is the establishment for a reason — and it isn't planning to fold up shop solely because Trump won in the fall.

What you have, then, is a party at odds with itself. Its most prominent voices (Sanders and Massachusetts Sen. Elizabeth Warren) are calling for radically overhauling the party and what it stands for. Its permanent political base remains in control of the party apparatus, however, and it views the changes that the party needs as largely superficial ones. Caught in the middle are Democratic voters.

Much of this divide has been glossed over in the months since the election due to the fact that President Trump has been busy chewing the scenery and leaving very little oxygen for other political fights. Democrats may even be able to gloss over these disagreements for the 2018 election, making the midterms a referendum not on their party but on Trump. (This strategy worked exceedingly well for Republicans in 2010.)

The problem will come in 2020 when it seems near certain that the Democratic primary process will force candidates not simply to slam Trump but also to offer their own positive vision for how they might govern if elected. What that vision will look like, as Sanders rightly notes, is anyone's guess.