Daniel Burns has an excellent essay on the subject in National Affairs. A taste:

Today, many American intellectuals go so far as to prefer liberal ideology (whether of the left or the right) over the real historical experience of liberal nations, including our own. This error has provoked much overreaction by today’s critics of liberalism. But the damage it has done to our political discourse goes far deeper than that.

The fact of the matter is that liberal ideology is false. It is false because all ideologies are false. Aristotle tried to warn us that politics is not subject to universal formulas and deductive syllogisms in the manner of mathematics or physics. After the experience of the 20th century, the burden of proof should really be on anyone who wants to assert otherwise.