Liberals accuse conservatives - Conservatives accuse liberals

Liberals accuse conservatives of refusing to recognise individual rights; conservatives accuse liberals of inventing law rather than discovering it.

Conservatives when they accuse liberals of asking judges to ignore what the law is and to substitute their personal views of what it ought to be – this being an abuse of power and a circumvention of the democratic process. 

This is a familiar Liberal sort of humbug: invoking the authority of a higher-order, (moral stance) ostensibly neutral position of principle in support of one’s partisan convictions

So should moral reasoning play  a role in legal interpretation, if so the temptation is to charge that  this theory of adjudication is just an excuse for reading one's  own moral and political preferences into the law

Dworkin’s first point is that when judges disagree over the correct decision in a difficult case, they are disagreeing over the correct interpretation of the law – over what the law is. 

There is not in such cases a plain fact as to what the law is, which anyone with enough information can discover. But that does not mean that there is no law at all, so that judges can make it up. Law, as Dworkin puts it, is an interpretive concept

To decide what the law requires in a given case it is necessary to consider, not only the facts of the case, the ‘plain language’ of the statute, and the examples of its previous application, but also the point of the law and of the larger institutions and practices in which it is embedded. All this is built into the practice of adjudication.

Legal argument always presupposes a jurisprudential foundation, even if it is concealed. And since the role of the judiciary can be justified only in terms of a broader conception of the legal-political order, it presupposes a political morality as well. 

Jurisprudence, however, is not identical with political theory, which can be Utopian in a way that jurisprudence cannot be.

 And since interpretation inevitably involves judgment about the best way to realise the purpose or point of the law, and of the system to which it belongs, it is a particularly delicate task to define the way in which the judge’s point of view can combine with other factors to yield a conclusion about what the law is which may not correspond to what he thinks it ought to be.

crabgrass in a smooth lawn.