It's difficult to assess the work of a jurist qua jurist in these raucously political times. Appellate judges are increasingly judged themselves not by the quality of their opinions or devotion to the rule of law, but by the extent to which their decisions are consistent with those called liberal or conservative, Republican or Democrat.
Judges are themselves responsible for the politicalization of their courts when they openly pledge allegiance to particular political or social positions. Justice Scalia, unfortunately, did so repeatedly and loudly off and sometimes on the bench, and as a consequence there is a tendency to focus, on his death, on his status as a conservative in a court increasingly divided in politics as is the nation itself. As our politics are increasingly mean-spirited, contentious and vulgar, so is our assessment of those who make themselves political figures, judges included.
I think Justice Scalia was very much an activist judge. But as a conservative activist judge he wasn't subject to the condemnation of other judges who were activists in liberal causes. Activist judges were once considered to be liberals almost by definition, but that time has passed. It's doubtful there ever has been or ever will be judges uninfluenced by ideology, but jurisprudence suffers when judges become overtly ideological. So, jurisprudence suffers now, as he nomination process consists of the questioning of nominees regarding their ideological positions only.
It may surprise some that Justice Scalia was a very able supporter of the rights of criminal defendants, thought flag-burning protected by the First Amendment, voted against an effort by the State of California to ban certain video games. He could be a witty and formidable champion of civil liberties. He was generally witty and clever, it seems, which can serve to relieve the ponderous nature of the law and legal opinions.
Perhaps his defense of civil liberties will be seen by some as consistent with his conservatism, but what is now and has been for some time described as conservatism in the United States has been less and less concerned with civil liberties, except those which assure the accumulation of property and money and those associated with the exceedingly broad definition of freedom of religion being used to favor certain religions. Nonetheless, his opinions in favor of civil liberties are what I think most important in his legacy. It seems to me that his conservatism became more like the restrictive, exclusive conservatism of American politics towards the end, though, and that is unfortunate.
He will be remembered as a jurist perhaps primarily for his championship of the somewhat bewildering doctrine of originalism. Originalism provides that judges in ruling on constitutional issues must divine the intent of those who prepared and adopted the Constitution. Ascertaining the intent of those 18th century lawyers and gentlemen is no easy task, however, and like scripture their writings may be used to support various positions. Then there is the undeniable fact that things have changed significantly since 1787, and it seems imprudent to assume that the Constitution should be deemed to reflect only the values and thoughts of those particular men of 229 years ago who would be dumbfounded by much of the world we now live in. It would seem to give little credit to the intelligence of those men to maintain that they would feel and think now just as they did then in light of all that has taken place in more than two centuries.
Perhaps he favored what he believed were 18th century values regardless of the fact that they would be those typically held by those then living and those who drafted and adopted the Constitution. That would explain his decisions which were in opposition to civil liberties as I would define them. His defense of laws against sodomy was disturbing, as it was premised on the position that states should be free to determine what is or is not acceptable conduct. More disturbing to me, however, were the decisions in Citizens United and the dreadful Hobby Lobby case. There it seems to me that he abandoned the defense of civil liberties while purporting to protect them. Finding money to be speech in our mendacious system is to assure than the liberties of some few will be preferred to those of others, as is finding that corporations runs by those with certain beliefs will be free to do things other corporations cannot.
Regardless, it can't be denied he was a formidable judge. We may prefer to see other judges on the Supreme Court for various reasons. It was sad that Learned Hand never became one of the Supremes. But we have seen worse on the High Court.