As for Haidt, I encourage you to learn about the work of John Jost, Haidt posits that conservatives an and liberals share two of the same moral foundations (harm avoidance and fairness), while conservatives have three additional foundations that they regard equal to those two (ingroup loyalty, obedience to authority, and purity). Jost's research demonstrated that the three additional moral foundations of conservatives is statistically associated with social dominance (belief your group is superior to others) and right wing authoritarian. In other words, people who hold those three conservative moral foundations are also more likely to believe in authoritarianism and that their groups should be dominant over others. It's almost eerie to think about Jost's findings in today's political climate.