Before Marx's Das Kapital gave the theoretical basis of the leftist political religion of Marxist socialism, essayist Thomas Macaulay wrote of religion in general: "The doctrine, which has been held by bigots of all sects, is simply this: I am in the right, and you are in the wrong. When you are the stronger, you ought to tolerate me, for it is your duty to tolerate truth; but when I am the stronger, I shall persecute you, for it is my duty to persecute error."
That's a description of all ideologues.
A dictionary definition of "ideologue" is "someone who behaves very strictly according to an ideology [belief system], and never doubts that it is right."
Ideologues, then, are certain that their ideology is absolute truth.
If reality, objective truth or morality clash with their ideology, it's reality, objective truth and morality that are false, not the ideology.
Among others, National Socialist Hitler and Marxist socialists Stalin and Mao, clung to their bigoted political ideologies with a religious passion that "justified" their persecuting "error" by slaughtering more than 100 million human beings and plunging hundreds of millions more into misery.
Now we're seeing here in America more and more bigoted ideologues of all kinds, mostly leftists, but not just leftists.
To survive, we must insist on a search for reality and objective truth, not blind acceptance of irrational, bigoted ideological "truth" that supposedly justifies inhuman, immoral actions (hating, demonizing, rioting, burning, breaking bones, murdering) to "persecute [perceived] error."