The answer to this question is more complex then you realize, my friend.
I know it does not rate as stunning political insight to say 'the left has substituted politics for religion' at this point, but I think the rational among us are sometimes unwilling to truly understand how literally true this statement is, and how accepting that can yield better insights.
Your average 'liberal democrat' is an middle-to-upper class Millennial at or approaching middle age. They grew up in an social environment that not only had increased irreligiosity, but where all the social incentives were aligned towards the public rejection of Christianity (particularly the evangelical variety) as marker of correct thinking. To borrow from the modern argot, to be Christian was to be 'cringe'.
However, while they may have rejected religion, they could not deny their own human need for meaning and purpose. It had to be replaced by something, and the first major events of a Millennial's young adulthood provided the avenue - the Great Recession and the 2008 election. Barack Obama cloaked himself in a preacher's mien, from the rhythm of his speeches to the imagery of his campaign. The gnawing desire for purpose was suddenly fulfilled in a newfound fealty to a political figure that had so effortlessly taken the forms of the old ways and related it to a new form of faith in 'progress'. This cadre - already broken over a failed start to life due to recession - were eager disciples.
The faith has spread ever since, and 16 years hence it has gained more and more converts with each passing season. Trump in particular was the greatest gift this faith could have received. It gave the faith a definitive enemy - a devil they could portray as the ultimate opponent, and solidify their their faith in opposition to him and those they deemed his acolytes. His actions were all given a sinister, near supernatural quality by the bishops and priests in the media class. He is 'evil' in specifically the way the Liberal Faith had always organized itself around. He is an avatar of all the 'wrong' of the United States that the Liberal Faith perceive, a heralded destroyer who must be heroically opposed by the righteous.
There are different levels of faith, of course. Your average Liberal Faith adherent might only know the basic forms, functions and words, but dutiful attend 'mass' in their social feeds and media appetites. The more invested in the faith know of the deep mysteries from which flow couch jokes and fevered whispers of creeping 'fascism' should darkness prevail. They serve as willing alter attendants, participating in the public rituals and intoning the shibboleths of the Liberal Faith as if it was second nature. The clergy of media figures and power brokers tend to the flock with regularity, seeing to their faith and loyalty in their purpose, carefully disabusing them of any doubts they have regarding their faith as they watch the world decay around them. After all, they must occasionally remind the faithful that one can be excommunicated for a multitude of reasons, though none is more heinous than Noticing. They must never Notice, lest they be cast into the MAGA abyss.
I want to be clear that you cannot save most of these people. They are of an intense faith - a darkly guided one that has made gods of the most unworthy people imaginable - but a faith nevertheless. They are largely immune to your reason. To attempt to shake them from their faith is to invite a hissing, angry response. But you should speak with them. You should understand them. Read their books, listen to their podcasts, and observe their rituals. Some will remain enemies, and understanding your enemy is wise. Some will waver in their faith and may be able to be brought back to reason - knowing the path they have tread will help you in that task. In the face of these forces, it is the most meaningful thing you can do.
I'm still trying to figure out why Democrats donāt live in reality with the rest of us. I think it has to do with too much recreational drug use and a painful longing to be seen as a good person, which stems from insecurity. Those two things, I believe, are at the heart of it.