Jonathan Rauch gives a full-throated support of liberalism in "Why You Should Feel Good About Liberalism: We need to get better at standing up for the greatest social technology ever devised."
What do we (or at least I) mean by liberalism?
Not progressivism or moderate leftism, as the term came to mean in postwar U.S. discourse. Rather, liberalism in the tradition of Locke, Kant, and the Founders. It is not one idea but a family of ideas with many variants. Its central philosophy is that all persons are born free and equal. Its operational principles include the rule of law, pluralism, toleration, minority rights, distributed authority, limited government, and (subject to the other requirements) democratic decision-making. Its distinctive method of social organization is to rely on impersonal rules and open-ended, decentralized processes to make collective decisions.
Embodying those notions are three interlinked social systems: liberal democracy to make political choices; market capitalism to make economic choices; and science and other forms of open critical exchange to make epistemic choices (that is, decisions about truth and knowledge). By transcending tribe, renouncing authoritarianism, substituting rules for rulers, and treating persons as interchangeable, liberalism achieves what no other social system can offer, at least on a large scale: coordination without control. In a liberal system, everyone can participate but no one is in charge.
In the context of human history, everything about liberalism is radical: its rejection of personal and tribal authority, its insistence on treating persons as interchangeable, its demand that dissent be tolerated and minorities protected, its embrace of change and uncertainty. All of its premises run counter to hardwired human instincts. Liberalism is the strangest and most counterintuitive social idea ever conceived, a disadvantage offset only by the fact that it is also the most successful social idea ever conceived.
Of course, it is imperfect. It does not solve every old problem and new problems always crop up. But all of the big social problems, from poverty and inequality to environmental degradation, war, and disease, are demonstrably better handled by liberal than non-liberal societies.
What are the defects in other political systems. Rauch's article contains sections dealing with each:
First: the challengers are either proven failures or vaporware.
Second: the challengers are enemies of equality.
Third: the challengers can’t self-correct.
Finally: the challengers are authoritarian.
This is an excellent detailed persuasive article. I highly recommend it.