It was a historic term, a surprisingly liberal term — and a nasty term.

That's the essence of the tea-leaf reading about the U.S. Supreme Court term that just concluded. Astonishingly — though the court is dominated by conservative justices — the liberal minority, disciplined and united, drove the direction in a startling number of cases, while the conservatives splintered into multiple factions.

The numbers tell the story. The liberals won in 19 of the 26 closely-divided ideological cases and eight out of 10 of the most important ones. Those numbers were compiled by SCOTUSblog, the go-to Supreme Court online journal.

"This is, by the numbers, the best term for the left in at least a quarter century," observes publisher Tom Goldstein.

Time after time, the liberals stuck together and managed to win over one or more conservatives — as they did in the case holding that states may refuse to issue Confederate flag specialty license plates. In that case, the court's most conservative justice, Clarence Thomas, joined the liberal four, providing the fifth and decisive vote.

Goldstein says that even taking the most centrist of the conservatives, Justice Anthony Kennedy, out of the equation, one or more members of the conservative bloc crossed over to join the liberals in 14 of the most ideological cases, while the reverse was true for the liberals only three times.

But as Goldstein observes, the liberals are, for the most part, just trying to preserve the status quo.

"A lot of what's going on with the left is that it's much easier to stick together on defense, when you're not calling plays and going for bombs and slants and trying to make a big difference and change the law," he says.

Court watchers cite other reasons for the liberal success this year — among them, that conservative activists just pushed their agenda too far.

"Several of the most important [liberal] victories that you see, are simply the court blinking at the extremism of certain [conservative] claims that were being put before it," says Yale Law School's Akhil Amar.

Another explanation is that the five conservative justices on the court have very different legal philosophies, and the cases this term showed those splits in vivid color. In all, the court's four most conservative justices wrote 78 dissents and concurrences, versus only 27 for the liberals.

Supreme Court advocate Walter Dellinger says the split among the conservatives is between "ideological, professorial conservatives" — Clarence Thomas, Samuel Alito, Antonin Scalia — and John Roberts and Anthony Kennedy, "who are more economic conservatives, which makes them more pragmatic and more realistic about what works."

Dellinger adds that 3-2 split "in some ways reflects the split within the larger Republican Party politically."

Or as Amar puts it, "The Reagan coalition is beginning to fray as the world turns, time passes, new issues arise."

The outcomes this term were so much of a turnaround that the liberal justices looked positively serene, even perky, in June, while the tone of the conservative dissents was unusually harsh.

"The bombastic tone of the dissents this term was over the top, even for Justice Scalia, who has a blood-soaked pen at his desk," Goldstein says.

"He wrote the nastiest thing I have read in any Supreme Court opinion," says Charles Fried, who served as the government's chief advocate in the Supreme Court during the Reagan administration.

Dellinger, who had the same job in the Clinton Administration, agrees.

"I've never seen that kind of really, deeply personal attack that basically says 'The author of the opinion is not just wrong as a matter of law, he's a jerk,' " says Dellinger.

That's pretty much what Justice Scalia wrote about Justice Kennedy's soaring rhetoric in the same-sex marriage case, calling it "pretentious," and "egotistic," and comparing it to "the mystical aphorisms of a fortune cookie." If I had ever joined such a vague opinion, said Scalia, "even as the price to be paid for a fifth vote, .... I would hide my head in a bag."

Fried, now a professor at Harvard Law School, says that in some ways, Kennedy's opinion provoked that reaction. He says that Kennedy should have focused on legal precedents instead of poetic passages. In particular, the court's 1967 decision striking down state bans on interracial marriage, and two more recent decisions dealing with same-sex relations and marriage.

Those three court precedents dictated the result, Fried maintains, adding, "That is the law. Suck it up!"

Even those who don't like the way the decision was written, however, see it as historic. The kind of decision that comes along only once in a half century.

Amar likens it to Brown v. Board of Education barring segregated public schools, though he points to critical differences. This time, he says the court was not leading the charge.

"It was just riding the wave, keeping up with the tide," he says.

In contrast he says the court in Brown was actually ahead of its time.

"Brown in 1954 comes along, before Martin [Luther] King [Jr.] appears on the scene, before a massive civil rights movement. So Brown actually starts the political avalanche," whereas "this time the court is actually following the lead of activists" and rapidly changing public opinion.

The court's other major decision at the end of the term upheld nationwide subsidies in the Affordable Care Act. And as Dellinger observes, Chief Justice John Roberts' opinion for a 6 to 3 majority was "surprisingly favorable" to the law.

"The first five pages of the chief justice's opinion ... is the best articulation of the case for the Affordable Care Act anybody has written," Dellinger says.

The decision did something else important. It sided with the liberal view that legislation should be interpreted in terms of its overall purpose and not by flyspecking a phrase here and there. And it said that the judiciary, not executive agencies, has the last word on such interpretations.

This was Roberts' 10th year as chief justice, and this term he proved to be something of the justice he said he would be at his confirmation hearings: restrained and deferential to legislative bodies where possible.

"In both the Affordable Care Act case and the same-sex marriage case, John Roberts was the only justice who took the minimalist position," says Supreme Court advocate Dellinger, now professor emeritus at Duke Law School. "He neither inserted himself in the Affordable Care Act process by derailing it, as his conservative colleagues would have done, and he didn't take the judicially ambitious stance, correct in my view, of invalidating the same-sex marriage position of all the states."

Indeed, observes Dellinger, Roberts was the only justice of the nine who took that minimalist position in both of these cases.

Roberts has not always demonstrated such a hands-off or deferential approach. He wrote the 2013 decision striking down the key provision of the Voting Rights Act, a law Congress had enacted and re-enacted by overwhelming votes. And he has repeatedly joined and written decisions striking down most of the laws that regulate money in election campaigns.

In short, just because the liberals happened to win a lot this year, doesn't mean they will in the future.

"There are liberal terms, there are conservative terms, and it largely depends upon what the case mix is," observes Stanford Law professor Michael McConnell.

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