A liberal is someone who believes we have already committed the exact amount of civil disobedience in the past required for the exact amount of human rights and that any contemporary disobeying of the establishment in pursuit of more human rights is unreasonable and problematic.

Liberals generally approve of the revolutionary action taken in the US in the past, because they can be insulated from the risk of taking an actual stand that's unsanctioned by their peers or the state. In reality, most opposed to rioting today would've opposed it back then too.

This isn't a universal truth, as there are exceptions. But the general ethos of liberalism vis-a-vis "progress" is that human rights can be achieved by citizens operating within the rules of the state, a state organized to violently prevent material progress from happening.

My opinion is that people who disparage revolutionary action today while applauding the examples of it they read about a textbook in 10th grade are people who are happy to reap the benefits of history without having the courage to participate in its ongoing process.