It is only when you understand that modern liberalism is not a political ideology but a religion that you can comprehend the liberal attitude towards dissent. To modern liberals, dissent is not dissent. It is heresy. It is sin. To disagree with liberal dogma is evil.
This also explains why modern liberals want to control every aspect of our lives. They live in constant fear of falling into sin. The only way to avoid sin is by constant vigilance. And sin is regarded as an infectious disease. If one person is allowed to maintain a sinful viewpoint or to live a sinful life is a threat to the entire Church of Liberalism. It is not enough for heretics to be marginalised and harassed - heresy must be utterly exterminated. The suppression of heresy is a religious duty. When liberals seek to destroy freedom of speech, when they seek to destroy academic freedom, when they force dissenters to conform to liberal orthodoxy, they are acting out of a sense of religious obligation. To show tolerance or mercy would be to betray their religious faith.
If liberalism were really a political ideology liberals would not be concerned by the existence of dissent. As long as a political party or movement can command the majority vote the existence of a dissenting minority is an irrelevance. But that’s not how liberals see it. Any dissenting minority must be extirpated or forced into conformity. The survival of even one heretic is an affront to religious truth. Every single heretic must be forced to recant.
Liberalism as religion also explains the attitude of one of the leading liberal sects, environmentalism, towards science. They tell us that as far as global warming is concerned the science is settled. The notion that science can ever be settled is a fundamentally unscientific and anti-scientific notion. It is a religious notion. There is no need to look for scientific evidence. Global warming is a revealed truth. It cannot be questioned. It is not subject to doubt. All that is required is faith. And religious discipline.
Liberalism today is more like a jihad than a political ideology. It is a war on unbelievers.