What do liberals / progressives / Democrats stand for?

Sara Robinson writes in The New Republic:

Every American over the age of ten knows what the GOP and the conservative movement stand for. Sing it with me now: low taxes, small government, strong defense, traditional families. See? You know the tune, and the harmony line, too.

OK, now: What do Democrats and progressives stand for?

Take your time. It's a tough question.

Give up? So have most progressives. Even the movement's most deeply committed members often have a hard time answering this one.

And that's a problem. Specifically, it's a branding problem. Conservatives have worked hard for the past 40 years to create a long-term brand identity for their ideas. Progressives haven't.

I'm generally wary of arguments in which someone defends their political side (whether it's a party or ideology or candidate or policy) by saying: Oh, our problem is we just haven't communicated well enough. This can be a cheap way to avoid confronting the deeper, more substantive problems with your side. I'm not saying there are no deeper, substantive problems with liberalism. But Robinson makes a pretty convincing case that liberals have spent many years letting conservatives run away with the race to create the strongest brand. (She mainly refers to conservatives vs. liberals/progressives. The article might have more precise if she had instead talked more about Republicans vs. Democrats, since that's what she seems to mean.)

More:

Being the Official Conservative Candidate allows you to bask in its reflected glow−which, in turn, gives you all kinds of automatic credibility with the voters. Even if people don't know your name and are unfamiliar with your record, they're strongly inclined to trust you because you represent a brand they're deeply invested in. You don't have to waste valuable time or energy explaining your policies or values (which are already understood), hiring brilliant and expensive strategists (because the voters are already on board), or even selling yourself very hard to the electorate (because they already trust the brand you're affiliated with: they'd even vote for Bonzo, as long he was a conservative). With all that elaborate cognitive infrastructure already in place, running your campaign is as simple as standing up and repeating the familiar conservative tropes, knowing that your voters are already emotionally hard-wired to respond.

Progressives, on the other hand, have never tried to brand themselves in any kind of organized, coherent way−which is why even progressive leaders are often caught flat-footed when asked about the core values our movement stands for. There's no self-defined narrative through-line that carries us from one election to the next (let alone from one decade to the next). When Democrats do engage in PR, they do it in the most ineffective way possible−in piecemeal one-off campaigns that are entirely too much driven by polls and focus groups, and not nearly enough by the imperatives of long-term brand-building and values cultivation. Instead, we do it in limited, short-term bursts that are dedicated to promoting a personality or an issue, not the movement as a whole.

Notably, even though she does spell out the core principles of the Republican brand (those 8 snappy words in the first block quote), she never makes even a tentative suggestion as to what the Democratic brand's core principles are, or should be.