A lot has been written in the past few days (and will be written in the foreseeable future) about the legacy of the late Ruth Bader Ginsburg, both as an advocate before the Supreme Court and as a long-serving Justice. I wanted to highlight something that might get overlooked in all that (although at least one other commentator mentioned it), an instance where she made a huge impact on an important part of federal law without any explanation of why she made the decision she did.

Sentencing in federal criminal cases changed dramatically in the 1980s. Up until then, judges had great leeway to impose a sentence within a broad statutory range, with release on parole at the back end further mitigating potentially harsh sentences. Confronted with great disparities in sentencing, a bipartisan law, the Sentencing Reform Act (passed in 1984) gave birth the US Sentencing Guidelines (which went into effect in 1987).

The Guidelines are a mechanistic system that converts not just the defendant’s offense of conviction but related conduct into an “offense level” that goes from 0 to 43. Many of the facts related to that calculation comes from judges, not juries, and can even include conduct for which the defendant was acquitted at trial. The Guidelines do a similar thing with a defendant’s criminal history, placing them in a Criminal History Category from I to VI. Where those two values meet is the Guideline range, where the sentence is supposed to be imposed.

Starting in 1987 judges, for the most part, were required to impose sentences within that range (exceptions were largely controlled by the Guidelines, too).

From the get go, defense attorneys argued that the Guidelines (and various state equivalents) violated the Sixth Amendment because they increased punishment for a defendant based on facts beyond those found by a jury (or admitted during a guilty plea). Judges finding facts, the argument went, shouldn’t be the basis for ratcheting up punishment. Courts weren’t interested, however, and the Guidelines helped to drive the country’s overincarceration problem for the next two decades.

Things started to change in 2000, when the Supreme Court held that a New Jersey statute that allowed a judge to increase the statutory punishment for a defendant based on a judicially-found fact violated the Sixth Amendment. Ginsburg was in the majority in that case, but the cause of the revitalized Sixth Amendment was really championed by her opera buddy, Justice Scalia. With that case in hand, defense attorneys once again began to argue that the Guidelines were unconstitutional. Now the issue was whether an increase in those Guideline ranges were an increase in the statutory maximum for a particular offense.

Nothing came of those arguments until 2004, when the Supreme Court decided Blakely v. Washington. Blakely involved a sentencing guideline scheme in Washington state that was very similar to the federal Guidelines. In a 5-4 decision, the Court held that those guidelines violated the Sixth Amendment. Notably, the Court didn’t prescribe any kind of remedy, instead remanding the case and letting Washington deal with it. Ginsburg was, again, in the majority.

After Blakely it was only a matter of time before the Court had to consider what this all meant for the federal Guidelines. In 2005 the Court finally dealt with the matter in United States v. Booker. The facts of the case lay out the starkness of the issue – Booker was convicted of a drug offense that carried a statutory range of 10 years to life in prison. His Guideline range, on the other hand, bulked up by judicially found facts about the amount of drugs involved, was 30 years to life in prison. Two decades in a cage is a hell of a thing to require based on facts found by a single person (and not even beyond a reasonable doubt).

Booker, as it turned out, was actually two decisions for the price of one. In the first, the 5-4 majority followed Blakely and held that the US Sentencing Guidelines violated the Sixth Amendment. In the second, a different 5-4 majority held that rather than leave it at that and let lower courts and Congress sort it out, the appropriate remedy to resolve the issue was to strike down the statutory language that made the Guidelines mandatory in the first place. Thus were the advisory Guidelines born, which we’ve had ever since.

What made for these two conflicting opinions? After all, most of the majority for the remedial opinion were dissenters from the other opinion (led by Justice Breyer, who helped draft the initial Guidelines). It was Ginsburg – she was the fifth vote in both majorities. But in a rare instance of opaqueness, she didn’t write an opinion explaining her decision. Sure, she joined the ones written by Stevens and Breyer that were the majority opinions, but she didn’t write separately to explain why she had a foot in both camps.

In a career that made a lot of impact on peoples’ lives, Ginsburg’s decision in Booker may be her most important. Since the Guidelines became advisory in 2005 hundreds of thousands of people have been sentenced as part of a system she basically created (for some idea of the numbers, in its last report to Congress on the impact of Booker, the Sentencing Commission noted that more than 85,000 defendants had been sentenced in the past year). Yet there was no sweeping opinion, no reading from the bench to spur Congress into action. Just a decision, made thoughtfully I’m certain, but without any transparency.

Are we – or, should I say, are federal criminal defendants – better off with the advisory Guideline scheme rather than whatever else Congress might have created? Hard to say, given how little experience the system has with juries finding sentencing facts. I will say that judges have seized their authority under Booker (and its progeny) to vary from and, in some cases, completely ignore the “advice” provided by the Guidelines. Still, they exert a kind of gravitational pull at sentencing and are pretty central to most proceedings. It’s the irony that gets me, I suppose. Ginsburg was arguably the Court’s most public face over the past few years. That she has had such a major impact without doing much more than casting a vote seems out of whack, but such is life. And the law.