That's an interesting take. I've come to the conclusion that the root cause of leftism (a word I don't like) is sin.
People that allow sin to control them still understand on some level that God's word is what fulfills us in life and His rules are what helps guide us to be the healthiest and happiest that is possible in our circumstances. Regardless some still embrace sin and when the fruit of their behavior is revealed they lash out like spoiled children who want to continue to sin but don't want to reap what they have sown.
The more they embrace their lifestyle of sin the more they hate Christians and Christ. Homosexuals, Drug addicts, the promiscuous, Adulterers, serial monogamists, megalomaniacs, and the majority of Politicians (but I repeat myself) fill their lives with sin. They wallow in it, take pride in it, and when it doesn't fulfill them or makes them ill or sick or incarcerated, they lash out at Christianity.
We are all sinners of course and it is only by the grace of God and the sacrifice of Jesus Christ that we are saved.
As an old Jesuit priest once told me, “you cannot have any favorite sin.” Though we are all sinners, what sets a liberal apart is the adherence and defense of his or his neighbors’ favorite sins.
On the other hand, it was the hippies who gave us awareness of organically produced versus factory farms, pesticides, and genetically modified foods.
It is strange that we now have to think of “food freedom” as something we have to defend.