1. Sir Isaiah Berlin – Gaus dissolves the negative/positive liberty distinction by arguing that moral obligations are about holding people accountable to “the reasons one already has.”  Both positive and negative liberty fundamentally rest on this logic for Gaus, and so the distinction is not nearly as important as interrogating the appeal beneath both claims.  Negative liberty is just a false way to bracket some liberty claims from others.  
2. Stephen Holmes – There is to be no “bracketing” of moral arguments in Gaus’ view.  Gaus believes that we come to give public justification to our social morality through the Deliberative Public Justification Principle (DPJP).  This is different from Rawls’ Original Position or Overlapping Consensus views of liberal agreement because Gaus believes that we come to this position as the people we are, not as people hypothetically screened by a “veil of ignorance” or by a commitment to reasonable pluralism that asks us to set aside moral controversies… which leads us to…
3. Communitarians – The Sandel-inspired communitarian critique of Rawls is simply irrelevant since Gaus is going to get largely Rawls-like things out of his view of social rules while granting the moral particulars of each individual that communitarians complain Rawls’ screens out of Members of the Public when he tries to get people to be reasonable and not rational.  Gaus gets the same contractarian deontic commitment out of his members of the public without making the move that offends communitarians.  Add them to the Gausian hit list.  
4. Michael Sandel – Gaus denies the virtue account of moral rules on multiple grounds.  Most damning is the fact that under experimental conditions, people do worse abiding by and enforcing virtue ethical rules than they do deontic rules.  Virtue ethics is a weird source of social morality given it’s weakness as a command: “X so that you are Y-er” does not have the same value as a social morality as “X so that you have more Y” (Instrumental/Utilitarian) or “You have a duty to X!”  
5. William Galston/Berlin (Again) – Gaus believes that the Value Pluralists insistence on the “incommensurability of values” breaks down upon examination.  Particularly, upon examination of work by Gaus’ long-time colleague Stanley Benn, many incommensurable values in the abstract are actually commensurable in particular instances.  Gaus argues between competing values we have indifference curves between them, and very rarely, if ever, do we find ourselves actually on the curve in a choice between personal values and social rules.  Usually the salience of a moral rule is either weak or strong compared to our values, and in the rare times that we are indifferent between them, then we’re indifferent between them… and then who cares?  Very rarely does the incommensurability of values actually generate massive amounts of moral ambiguity in terms of what our obligations are morally… this seems to both match our intuitions about moral decision-makers and also explains why. even to a value pluralist, some moral decisions seem obviously “below the moral floor” even while they claim incommensurability.  

I’m not sure where this book is going still or if Gaus’ project succeeds ultimately, but if it were to, it would be very exciting… if for no other reason than it would clear out a lot of the detritus of 20th Century liberal political thought.