In fact, as the Democratic party has moved to the left over the last four years, they have actually done worse among their base voters. They’ve lost a good chunk of their support among nonwhite voters, especially Hispanics, and among young voters. Since 2018, Democratic support is down 18 margin points among young (18-29 year old) voters, 20 points among nonwhites and 23 points among nonwhite working class (noncollege) voters. These voters are overwhelmingly moderate to conservative in orientation and they’re just not buying what the Democrats are selling. Moderation = Democratic votes.
Ruy Teixera, "Ten Reasons Why Democrats Should Become More Moderate"
It depends on how you define "moderate".
A guy like John Fetterman is a down-to-earth moderate on culture war issues while at the same time being a Sanders economic justice progressive. Is he a moderate or an extremist? Kyrsten Sinema is a corporate shill who's left-of-center on sexual politics issues. Is she a moderate or an extremist? Raphael Warnock is a Christian pastor who is progressive on economic issues. Is he a moderate or an extremist? Which candidates better represent future electoral success for Democrats in "moderate" purplish states? It's obvious to me--the two that represent progressive economic issues that benefit the bottom 80% while maintaining moderate positions, i.e., reasonable and respectful to both sides, on culture war issues.
So what does Teixera mean by "moving left"? Is he concerned about moving left on progressive taxation, providing affordable childcare, affordable prescription drugs and health care, cleaner air and water, policies to manage climate change, better support for K-12 education, better training programs and financial support for displaced workers, better infrastructure, expanded social security benefits, saner gun safety legislation? Does anybody really believe that normal Americans in the bottom 80% oppose more progressive policies on these issues? It's only special interests who oppose them, and too often being a "moderate" means being in the pocket of special interests. Does moderate mean splitting the difference with Republicans who are against progress on all these things for no good reason except that they are against government doing anything?
Or does Tuxeira mean by "moving left" moving toward cosmopolitan elite values and against traditional populist values? That's different altogether. I've been advocate for moderation on divisive culture war issues since forever, but that doesn't mean that you should be a moderate on economic issues that benefit most Americans. The two tend to get mashed together in the media and so therefore in the publican imagination, but they should be separated out. Moving left on economic issues is not a loser if Democrats can find a way to regain their lost reputation for being the party of the little guy, which they lost when they became the party of cosmopolitan, Neoliberal elites. Becoming the party of the little guy means accepting that most, whether they are white or people of color, are more culturally conservative.
So what moving Left means for non-elites is not so much about economic issues, but about cultural and identitarian politics. I understand that identitarian politics is important for the Democrat base--the educated, urban elites and Democratic donor class who dominate the party. I understand that for much of this base economic and cultural justice issues go hand in hand, and I'm not saying that the identitarians should just shut up. I am saying that coalition building requires that factions with shared interests find a way to agree to disagree about the issues that divide them. Woke Neoliberals are greater impediment to substantive progress than culturally moderate everyday Americans.
The problem with any party, whether on the Right or the Left, is not whether its base is morally or intellectually correct, but that those in it tend to be absolutist and unwilling to compromise. And nothing is more alienating and more obstructive to effective coalition-building than factions that take absolutist positions. Nothing generates backlash and oppositional behavior and attitudes more intensely. Absolutists persuade no-one except other absolutists or the weak-minded who go along to get along.
The whole point of coalition building is to de-emphasize what separates and emphasize what unites. Clearly this is a lesson that the Republican Party seems incapable of learning because of the way that its absolutists dominate. The Democrats are not nearly so far gone as Republicans, but the absolutists among them impede their taking advantage of an historic opportunity to win back the more culturally moderate Middle. This 'middle' is willing to move Left on economic justice issues but won't because they dislike and distrust so much the Democrats who would take them there. If Democrats don't do it, the Republicans will eventually wise up and find a way to do it. Populist sentiment already leans their way. So Democrats--wise up. Find more John Fettermans and Raphael Warnocks. And ignore the Gavin Newsoms and empty suits who otherwise check all the boxes like Kamala Harris.