The “liberal case” for Brett Kavanaugh is the same as the liberal case for every other Republican judicial nominee: he is smart, highly qualified, open to changing his mind based on evidence, and definitely not an ideologue.
In fact, it is just an immense coincidence that this brilliant, centrist, pragmatic man happens to have ruled without exception in favor of rich people, big corporations, and social conservatives in the past. That’s just where the evidence has taken him! Nobody should assume that he’ll do the same thing in the future, and liberals should be ashamed of themselves for getting all shrill about this.