The Who demonstrate poetic prescience in their song Won’t Get Fooled Again in the lyrics “Meet the new boss; same as the old boss.”
I think it would be helpful to define the old legalism that I grew up with before describing the new legalism.
Growing up in the Church of the Nazarene, (and later in my understandings of much of what is presently termed the “religious right” - a term more often derided with disgust than with description), goodness and morality were sometimes defined as behaviors in which we did not participate. For example, “we don’t smoke, and we don’t chew, and we don’t go with girls that do” and “Beer is bad and whiskey’s worse. We drink water; safety first.” There was a time when lipstick and jewelry were frowned upon and ladies wore white gloves and hats to church. Men wore ties; people were expected to come to church in their “Sunday best.” Getting a divorce was uncommon and often held a stigma. I could on and on about such things and many of them are relics of the past that rightfully should be left in the past. Surely, we are much more enlightened today and far better off than our predecessors. Aren’t we?
One of the lessons of history is that perspective and context of the past can help to see the context of the present. For example, while some lament the loss of “the altar call,” it changes our perspective when we realize that altars as we knew them in protestant traditions were not around until the 1850s or thereabouts. (How did people come to the Lord before then?) In our generations, their use evolved from “mourner’s bench” to “communication station” to irrelevant in some places. I would venture to say that people might have trouble recognizing at any point in the history of the church that was back a few generations.
Some people compare our present Church period to an earlier Church period and feel superior in almost every way. New ways of thinking and diversity must surely be a renaissance for the Church. It is a hard task to see how our period fits into a continuum of change and realize that we are not really all that different from the past, but merely different players with a different set of issues. This means that the past was not as bad (or as good) as we might think it was, and neither is the present as good (or as bad) and we might think it is.
So what is the new legalism? Just like the old legalism, new legalism also focuses on the “what we [should] do” as opposed to “who we are to be.” Just as we did back in the day, the reasons why we took Saturday night baths and shined shoes on Saturday night  gave way to routine behaviors that were passed on to our children with the reason that “it is what you’re supposed to do.”
Some shifts in “approved behavior” were merely a pendulum swing that flipped an old way. For example, Pentecostal expression was part of the COTN in the beginning, but that gave way to behaving “properly and reverently” in church, which is now seen today as not participating or unenthusiastic about God, or sometimes is labeled “a dead church.” (“There’s no life at the church where they cling to old hymns and rituals.”) We’re supposed to know a tree by its fruit, but judging these behaviors is not indicative of anything more than a subjective viewpoint on worship expression.
I don’t know who observed the shift in Church focus from “getting saved” to “doing good things” but I think the Church has shifted in its emphasis. Whether this shift is good, bad, or neutral, it is hard for me to tell except by the guidance of prior shifts and what Scripture has to say. Anyone who has discussed the roles of faith and works should see how the two are mutually inclusive. However, when either is given too much preeminence such that it overshadows the other, one can either become “so heavenly minded as to be of no earthly good” or stray into the legalism of works righteousness. (Smoke and drink were the old bogeymen. Today’s focus is more on sins of omission and sins against nature.)
So what are the new legalism “sacred cows?”
Social Justice - What is not to like about fairly “distributing advantages, assets, and benefits among all members of society?” It is good and right to care for the poor and disadvantaged.Legalism is a good thing that is perverted; bent out of shape; placed in greater importance than more important things. Jesus said, “Woe to you, teachers of the law and Pharisees, you hypocrites! You give a tenth of your spices—mint, dill and cummin. But you have neglected the more important matters of the law—justice, mercy and faithfulness. You should have practiced the latter, without neglecting the former. “ – MT 23:23 NIV Jesus is saying that it is a good thing to tithe one’s mint and cumin (if you’re a good Jew); it is something that “should” be practiced - like social justice and resource management – but when something good usurps the more important things, it becomes just another legalistic behavior. Neither endeavor makes a person more righteous, any more than the point of a sword was able to make a true religious convert.
Resource Management - We should be stewards of our environment. We should not abuse the gift of this earth that God has lent to us.
So how should the Church act with purity of motive and virtuous action? My father told me, “When we ask ‘what do you stand for?’ we get pulled apart… but when we say, ‘Who do you stand for?’ (as in Jesus), we are one.”
The Church has abdicated its primacy of being a spiritual beacon in favor of being a political moral compass. We point people to good causes rather than to Jesus Himself, going so far as to indicate that Jesus sponsors our good causes. (Why would he not?) Where the Church has fallen short, we applaud and encourage the partial and compromising measures of the secular government to do the good the Church has failed to do. As long as these half-measures are acceptable to people in the Church, then the Church is truly in a post-Christian era.
 One morning as the people were filing out of church, the preacher told my father-in-law not to bring “that hussy” back to church – within her hearing – because of her make-up. That “hussy” was later to become my mother-in-law who had gone to modeling school and wore lipstick on that day. (High fashion.)
 Saturday night baths and preparations like shoe-shining were necessary to do on Saturday night because of observance of the commandment to “remember the Sabbath Day” to keep it holy, which involved a practicing a very different day than the previous six.
 I suppose you all know the joke well enough for me to give only the punch line: “Shh. Those are the Nazarenes. They think that they are the only ones up here in heaven.”
 Someone pointed similarly to hymnology as a means to gain insight into the focuses of the church at different times in history. I cannot cite specific examples with authority, but in the early 1900s when times were especially hard, songs might speak of “rest beyond the river” and even further back noting songs borne out of American slavery (gospels). It would be worth a study (IMO) and if someone has information about this, it would be very interesting to read.
 The seven churches in Revelation 1 may be one place to judge our present Church.