You hear that liberalism lacks an idea of the common good, but I think that's a mistake.
The fault of the utilitarian doctrine is that it mistakes impersonality for impartiality.
A just system must generate its own support.
Public reason arguments can be good or bad just like other arguments.
Justice is happiness according to virtue.
Different political views, even if they're all liberal, in the sense of supporting liberal constitutional democracy, undoubtedly have some notion of the common good in the form of the means provided to assure that people can make use of their liberties, and the like.