It doesn’t say that they tend to favor institutions in the abstract. It says they tend to favor institutions and practices that enhance social order and historical continuity.
Social order is simply referring to a society that is undergirded by organizing social structures and institutions. These don’t have to be the institutions that have been core to the American liberal project since the New Deal. Conservatives have long derided even these meager programs.
Appeals to these types of institutions and constitutions are more inherent to liberalism rather than conservatism. The big issues with these terms in American political life is that there are a ton of “conservatives” who are liberals by any normal political definition. One thing the Trump era has brought us is a realigning of American political terms along these more traditional lines: socialists/social democrats, liberals, and conservatives.
The institutions and social structures that MAGA relies on are at a much more base level than constitutions and the liberal norms. The nuclear family, patriarchy, traditional religion, etc. Conservatism has been steeped in these principles since its inception.
Think about it this way: Edmund Burke surely thought he was favoring institutions and practices that enhanced social order and historical continuity when he opposed the French Revolution.
There are some that think conservatism started with Buckley, but I think that’s hogwash honestly.