Democrats doing their centrist bullshit are captured by corporate lobbyists.
How Money Works explained the saturation of money in politics (here, on YouTube), and it runs effing deep.
Essentially anyone who gets elected at a federal or state level has to decide between two options. Do they:
a) Want to serve their constituency and fight for the common voter? Or...
b) Get really rich and join the ownership class (the 0.1% or higher)?
And during the 90s and Aughts it became normal in both parties to choose option b) Apparently, it's super humiliating, because the official no longer does any actual legislating. Instead, lobbyists come to them with premade bills (and promises of campaign contributions and dark money and stuff) and the lawmaker only gets the prize if the law gets passed verbatim. There is no doubt from the official that they're being played and owned, and that their constituents are going to suffer for their corruption. But then, the money is awesome, and so they get used to it.
We're actually seeing how removed some of our officials have become from the common American experience, with countless let them eat cake moments. We'll hear an official express in a soundbite that they don't understand or care about the concerns of the commoner.
And yes, we're seeing other signs of capture in the establishment Democratic party. News came out not long ago (here from Politico) that centrist Democrats are getting worried now that progressives and SDAs are winning elections and becoming a larger portion of the big tent. Evidently, it's a coalition party so long as the left side offers its votes but not its opinions.
I think Democratic voters are tepid about merely keeping the Republicans at bay (even though the consequences are awful when we fail) but actually get excited about voting in candidates when they have specific platforms they want to do while in office. Taking a page from Ross Perot in 1988, a lot of people got excited because he had a very specific plan. I think voters would like to see detailed plans rather than ambiguous objectives.