On the surface, Supreme Court justices seem to have it pretty easy: They decide only around 70 cases per year with a written opinion, meaning each of the nine justices on average gets assigned to write fewer than nine majority opinions per year. They do not sit for regular argument in July, August, or September; and some justices use part of those summer months to moonlight as guest law professors in exotic locations.

But every so often court watchers are reminded that these justices are working very hard behind the scenes by reading briefs, exchanging memos, and debating outcomes. Case in point: The justices issued an order and a dissent in a Texas voting rights case at 5 a.m. Saturday morning. Supreme Court reporters stood by all night for the ruling. The holdup apparently was Justice Ruth Bader Ginsburg’s six-page dissent, joined by Justices Elena Kagan and Sonia Sotomayor.

The Supreme Court allowed Texas to use its voter ID law in the upcoming election, even though a federal court decided a few weeks ago that Texas’ law violated both the Constitution and the Voting Rights Act, and that Texas engaged in intentional racial discrimination in voting. The trial court had barred Texas from using its law this election, but the United States Court of Appeals for the 5^th Circuit reversed that decision last week, and the law’s challengers went to the Supreme Court, where, as expected, the court sided with Texas.

The Supreme Court’s order was consistent with some of its other recent orders indicating that lower courts should not change the rules of running an election shortly before voting begins. I have dubbed this rule the “Purcell Principle,” for a 2006 Supreme Court case so concluding.

The court had to decide the emergency request very quickly—early voting begins in Texas on Monday morning—but Justice Ginsburg did not need to write her extensive dissent. The week before, when Justices Samuel Alito, Antonin Scalia, and Clarence Thomas dissented from a Supreme Court order putting Wisconsin’s voter ID law on hold, their entire dissent was only a few sentences. It was a dissent which disturbingly treated the right to vote as less important than deference to the Court of Appeals judgment, kind of an Anti-Purcell Principle.

Sometimes justices disagree with emergency court orders such as these and do not even bother to write a formal dissent. And recently, as Slate’s Dahlia Lithwick has noted, the majority has not been explaining its various orders in cases from voting rights, to abortion, to same sex marriage, at all.

So why did Justice Ginsburg keep the court and court-watchers up all night for a relatively lengthy dissent from an order issued with no majority opinion? There is no way to know from the outside, but my guess is that she wanted to make an important statement about how the Supreme Court should handle these voting cases going forward and to publicly flag where she believes the court is going wrong. Like a rare oral dissent from the bench after a written opinion, this middle-of-the-night dissent calls attention to what Justice Ginsburg likely sees as a grave injustice.

To begin with, Justice Ginsburg pushed back against the Purcell Principle. Sure, it is important to make sure that courts do not change election rules at the last minute, but there were other issues at stake in deciding on the Texas stay. For example, the trial court—after a full trial on the merits—found that Texas was intentionally discriminating against minority voters. It appears to be unprecedented to let a law that was deemed racially discriminatory go into effect simply to avoid the risk of voter confusion and election administration inefficiency.

Further, Justice Ginsburg highlighted the large discriminatory effects of the law. Texas had what Justice Ginsburg called “the strictest regime in the country,” with many forms of identification such as college student ID cards unacceptable.* Unlike other states, Texas did not have an exemption in the law for those who were too poor to afford the certified birth certificate or other documents necessary to get the “free” ID card—a card which Justice Ginsburg said Texas did not let people know was widely available.

Justice Ginsburg also highlighted the trial court’s findings that there were hundreds of thousands of voters potentially unable to get IDs because they were hours away from the government offices issuing IDs. The state had not made reasonable efforts to get IDs into the hands of everyone who wanted them.

Importantly, Ginsburg concluded that the effect of the law in its entirety would be to diminish voter confidence in the system. “The greatest threat to public confidence in elections in this case is the prospect of enforcing a purposefully discriminatory law, one that likely imposes an unconstitutional poll tax and risks denying the right to vote to hundreds of thousands of eligible voters,” she wrote. The Texas case will likely make it back to the Supreme Court, perhaps next year, after the 5^th Circuit takes a full look at the case. While the Supreme Court’s vote on the stay order in the Texas case does not tell us for sure how things will go when the court gets to the constitutional merits of the challenge, the five conservative justices on the Supreme Court are likely to let Texas put its ID law in place because of their general view of the scope of the Constitution and the Voting Rights Act. No doubt Justice Ginsburg knows this.

But she’s not going down without a fight, and if this dissent stands for anything, it’s for the proposition that even if the court opts to erode the right to vote by way of unsigned orders at dawn, Ruth Bader Ginsburg will not let it be invisible to the rest of us.

Update, Oct. 22, 2014: In her dissent, Ginsburg mistakenly wrote that a veteran’s ID card was not an acceptable form of identification for voting. She has since corrected the dissent. (Return.)