I mean, generally it’s because they think anyone to the left of them has no chance of changing anything so they believe that they must choose the D in order to stop the F. They gave up on their own values so often and so thoroughly that showing them that supporting the D is equivalent to supporting the F is tantamount to a direct attack on their core Identity and forces them to confront themselves and their compromises. This causes rage.

1. they are not leftists
2. they have sufficient perceived privilege (both on the domestic and international stage) that they would advocate voting for the Democratic party

Usually the contradictions of capital would have to affect their personal material conditions enough along with the correct resonating anti-capitalist perspectives (and hope they do not drift further towards fascism) for them to be persuaded otherwise.

However, history suggests that the systems of formal and informal education (let’s say schooling and media, for examples) can sometimes degenerate sufficient development of collective empathetic intelligence; the murder of Rosa Luxembourg being one of the more famous example markers in European history of liberals turning more abruptly to fascism rather than marxism.

This is not to say people are unchanging. That would be a non-scientific and non-dialectic approach. A lot of us here were liberals once.

There are various paradigms that expand on this including labour aristocracy, manufactured consent, unequal exchange, neo-colonisation and imperialism, idealism and liberalism; not withstanding racism and American Exceptionalism.

Lots of authors to choose for further reading including Lenin, Gramsci, Walter Rodney, Michael Parenti, Vijay Prashad, Zak Cope, Edward Said and D Losurdo to name a few from the top of my head.

/ edited for clarity

the dems represent their interests well enough

They believe in the dichotomy of two parties, that politics happens once every 2-4 years (midterms maybe and presidential election for sure), and that nothing else is or ever can be viable. It may be an offshoot of capitalist realism in some way: electoral realism “it’s easier to imagine the end of the world than the end of the hegemonic party dichotomy.” They are similar in that both US capitalism (and imperialism) and US electoralism are contributing to bringing about the end of the world, if they can get away with it; this is the weird thing about it. The same stuff that people think can’t end unless the world ends is stuff that’s threatening to end the world.

So in that regard, if you criticize or you say you can’t take a side in the dichotomy in good conscience, it’s framed as if you’re saying “I’m okay with worse than this.” In practice, we know that for communists, this is the opposite. That one of the realizations within it is to understand “it keeps getting worse regardless of which party I side with, so why fray my conscience further and expend my time and energy by pretending I can make it less bad through it?”

Underlying this is an important question of power. When people say stuff like “vote blue for now and we’ll push them left when they are in office,” if they are not backing it up by saying “we will push them left with XYZ union/cadre/strikes/etc.”, it is an empty declaration and even then, it must have logistical longevity behind it, not just vague notions of striking… I mean, Biden blocked the railroad workers strike in 2022: https://www.reuters.com/world/us/biden-signs-bill-block-us-railroad-strike-2022-12-02/). The US power structure has no accommodation for reasoned and conscientious appeal, and even its accommodation of unions and striking workers is limited.

All of this is to say, power, logistics, and direction are what defines what happens next, not shaming, desperation, and hopelessness. People who view the democratic party as a way to block the republican brand of fascism are only taking power seriously by proxy. It is power that never once comes near their hands. Until/unless they accept this, they will put more responsibility for your voting habits on you than you actually possess. People grassroots gathered around AOC to push her into office and she turned out to be terrible on critical issues. People grassroots gathered around Bernie to push him into the presidential office in 2020 and couldn’t even get him to win the democratic nomination without party power brokers having the other candidates form around Biden.

It’s not comforting to acknowledge how controlling the US actually is if you take away the pretense of choice. And without an anti-imperialist, anti-colonial, and communist political learning and context, it may lead someone to simply feeling depressed, slipping into doomerism or disengaging from politics entirely. All of the red scare propaganda helped create a sense that no alternative is viable and that considering a communist one is tantamount to wanting to eat babies.

We all live with some degree of delusions in varying degrees. For these people (the ones who are not themselves among the ruling elite), the safety of the democratic party is one such delusion. The belief that it is the only realistic bulwark against the terrifying and vocally rabid republican party. If they give that up, they are not a protected and valued citizen in a safe land with a history of stable reform. They are an exploitable resource in a land run by white supremacist elites who may have just not gotten around to exploiting them yet on account of having people lower on the developed totem pole of caste to go after first. They live in a country that isn’t for them. A country that views them as less than human from day one. It’s more comforting to believe good people are trying to make it work for good.