So...I thought I would explain exactly why I call out centrist democrats so hard and believe them to be basically moderate republicans, or at least have more in common with moderate republicans than social democrats.
Explaining the spectrum
I tend to believe in this general 7 point likert scale for politics
1) Communists
2) Democratic socialists
3) Social democrats
4) The great melting pot of moderate liberalism
5) "Centrists"/moderate republicans
6) Conservatives
7) Fascists
I'm around #3 on that scale. 5 is where moderate republicans and even some centrist democrats start blending together. The political overton window since the 1980s has ranged between 4 and 6. DSA candidates are #2, actual socdems are #3. Illiberal extremists are 1/7.
Discussing worldviews
With that said, I wanna do a brief dissection of a moderate third way democrat's worldview.
Theology/Philosophy- Variable, but for the sake of argument, many of them are Christian. However, they're mainline Christians, not fundamentalists. They tend to have one foot in the Christian worldview and one foot in the secular worldview. They'll profess beliefs in Christianity and reverence for its doctrines, but also tend to not take stuff literally at times. This leads to a fragmented worldview similar to what I had in the late 2000s/early 2010s. They'll be surprisingly reasonable one minute but then fall for the same old religious BS at the same time. Again, kinda all over the place. Examples of this are Hillary Clinton, a methodist, her pro life VP, Tim Kaine, Joe Biden, a catholic, John kerry, also catholic, etc.
Some can also be new atheists though, especially older generation ones like Bill Maher and Richard Dawkins, who are boomers and have always had that more moderate liberal mindset.
Morality- Due to the conflicting nature of their metaphysical worldview, you get that leaking into their morality. Probably stage 4 on kohlberg's stages of morality, indicating they still get their morality from external sources and have a relatively fixed understanding of the world. May have some conservative brain rot in there as a result. Think Hillary Clinton, who was pro life personally but pro choice politically. Anti homosexuality personally, but pro LGBT rights publicly. Internalize the protestant work ethic and as a result generally believe all humans should work and inherently believe in a more limited role to safety nets. Think clinton again with "god given potential" rhetoric, Biden with "work has dignity" rhetoric, etc. It stems from this inherently conservative mindset driven by Christianity. Like, you generally dont have the free thinking secular humanist stuff, even if their religious worldview is tempered somewhat with humanism.
Psychology/sociology- Due to the undercurrents of Christianity, still believe in free will, moral accountability, personal responsibility, and probably believe that humans are sinful or evil in some way. They dont deny social sciences like the right do, but these moral beliefs do leech into their politics.
Law/politics- They're less likely to support overt christian nationalism, but the christian worldview leaks into their morality, which thus influences their politics, serving as a moderator. They tend to believe a lot of similar things as the right, but more in a "let's not get carried away with it" sort of way. Again, they might have issues with abortion, or LGBT rights, where they come out in favor of it when public support is on that side, but if it isn't, they'll be fine with throwing those issues under the bus and upholding a moderate consensus. Again, public position vs private position.
Economics- The same is true with economics. Their morals are basically the same as conservatives. Capitalism inherently good, it has SOME flaws, but ultimately more pro capitalist then, say, I would be. Still believe everyone must work, focus on "equality of opportunity" and job creation. Limited support of safety nets, and this is where they bristle up against progressives.
Progressives tend to not be limited by this christian impulse. They're more willing to acknowledge that these systems exist for humans, not humans for the systems, and are more willing to change things. Progressives often support large, universalist safety nets, and centrists just freak out about that. You cant just tax people and redistribute wealth, that's immoral. Like, imagine the hard right believes that everyone should work and what people get they get, and if you dont get enough you deserve to suffer. Moderate liberals look at that system, recognize the moral justness of it, but due to being moderated by humanist impulses, want to soften the edges of it. But still, they dont go far enough because they ultimately believe in the same moral system conservatives do, just with more nuance. And then you have "the left" come in and question the very ideals underlying the system for whatever reason and they end up having a moral panic, saying I CANT SUPPORT THAT and blah blah blah. Which is why in this moment, they're joining republicans in this weird mccarthyist fervor to punch left at social democrats. because despite claiming to support social democracy, their morals are still fundamentally conservative in nature. And I realize it, and they seem to not see it that way.
History- I wanna include this before wrapping back around to discussing economics more, but I do wanna discuss this a bit too. Because of the fractured worldview, they often dont have a very coherent account of history. Biblical Christianity offers narratives based on myth. The more I study history as a secular progressive, the more driven I am to conflict driven narratives about how our society has been driven by the authoritarian impulses of a ruling class. And that they use the conservative ethic to entrench their power. While I inevitably support some iteration of existing institutions, I'm fine with more heavily reforming things, wanting to avoid the problems associated with "leftism", but I kind of understand how a lot of stuff conservatives and even these liberals take for granted are social constructions that dont always benefit people and they we should challenge some of them. But because those liberals are de facto conservatives, defending that belief system and institutions in its image, they end up punching left, even at social democrats and the like.
So yeah, basically, the centrist liberal is like half conservative, half humanist. They are willing to debate the nuances of the conservative worldview, tempering that with rationality, but they'll also temper their rationality with belief in tradition and that christian worldview. Again, their philosophical bases are a hot mess, with a lot of them operating from this highly inconsistent moral framework that is held together by duct tape and cognitive dissonance. It works, quite frankly, because IMO, a lot of these guys dont think about this stuff very hard....they're more well read than conservatives, giving them a bit of a superiority complex over the "the world is 6000 years old" guys, but yeah, as someone who was once there, when I thought about it enough, this stuff collapsed like a deck of cards.
And yeah, that's why when actual progressives start saying the status quo is unjust and start wanting more drastic changes, they lose their crap. From our perspective, the changes are just rational, and without that christian influence in my worldview, moderating doesnt even make sense. Why should we compromise with this weird irrational worldview? That's how I see it. But lacking that irrationality, the moderate will scream about how we dont share their values and start siding with conservatives over us.
Briefly discussing humanism vs marxism-leninism
Now, with that said, let's separate liberal progressivism and social democracy from hardcore leftism.
Metaphysically, both humanism and MLism start out as atheistic, naturalistic philosophies. Which is why atheism is often associated with MLism and the right screams about atheists killing millions of people. Because MLs did that.
However, when you start delving into MLism, you start noticing that these guys made a state sponsored political religion around the USSR, where Marx is treated as a prophet, his writings as holy doctrines, and where the leftist dictators of the 20th century are also venerated to a large degree.
Humanists....dont view things this way. We're more moderate and even handed ourselves. We tend to pride ourselves on not having gods, masters, or treating anything as sacred. Just as we question the right and christianity, we question the left and marxism too. While marx does have some valid points about capitalism's flaws, his calls for revolution, abolishing the system, and establishing socialism and communism are a failure. So I would consider humanism a more LIBERAL or social democratic philosophy, while leftism is its own animal.
On religion, humanists are generally pro first amendment and even if we dont like religion, we're pluralists on the subject. Secularism is about protecting freedom. MLs want state sponsored atheism, not mere secularism.
And it just diverges from there. Humanists will come back around pointing out capitalism has some advantages and communism never worked, whereas MLs are so dedicated to destroying capitalism that they end up going to weird extremes.
So make no mistake, leftism is a quasi religion dedicated to destroying capitalism and replacing it with socialism, communism, or anarchism, while secular humanists are more even handed, recognizing that yes capitalism is horribly flawed, but also that it should exist in some form. With me, I tend to have the framework of using sociology to analyze economics both from functionalist and conflict driven perspectives, recognizing value in both, and the two moderating each other, the way for a moderate democrat, christianity and secularism mdoerate each other. But for me, this dualistic approach works, as I can recognize the objective value in something while also seeing how it sucks.
So for me, I got my own moderating influences in pure rationality that stop me from going down the ML path and drinking their kool aid. I cant say the same of all leftists. I do think the threat of illiberal leftism is a long term threat to be kept an eye on. BUT....let's face it. Centrist libs are just moderate right wingers. So I guess we can create a new scale here. From left to right.
1) Marxist-Leninists- Left wing crazies
2) "Democratic socialists"- Moderate left wingers, still support the abolition of capitalism, but seem to have learned from some of the mistakes of the #1 guys
3) Secular humanists- Relatively even handed, criticize both christian capitalism and marxism-leninism, end up with reason driven progressivism
4) Moderate liberals- Half secular humanists, and half christian capitalist, end up being the moderate wing of capitalism
5) Conservative christians/capitalists- The real die hard ideological believers in capitalism, tend to support the belief system without limits, ignoring the flaws and downsides
Like that's basically how I'd frame it. 1 and 5 are the extreme versions of ideologies. 2 and 4 are moderate wings that tend to temper their respective ideologies with some level of rationality. And 3s are just the purely rational people who arguably end up supporting some form of interventionist capitalism. You can even say "humanist capitalism" or "human centered capialism", but I'd also say a form of social democracy works here too.
And in America, the debate is between the 4s and 5s. The "left" is basically 3s, 2s, and occasionally 1s. And given the state of DSA, I think the overall direction of that faction is 2.5, with some being socialists, others being social democrats, but generally agreeing on short term priorities.
And yeah, being a 3 is frustrating these days, its like you dont fit in anywhere. The 4s and 2s are both obnoxious, not even getting into the 1s and 5s and their weird ideological purism. But yeah. That's how I see it.