Recent months have witnessed a steady stream of stories about state legislatures attempting to attack or outright overturn the will of state voters—from discriminatory voter ID laws to the naked power grabs we’ve seen from legislators in Michigan, Wisconsin, Florida, and elsewhere. While attacks on the right to vote rightfully elicit outrage and media coverage, far less attention is paid to an equally pernicious threat against democracy: bias infecting our juries and their verdicts. This term, the Supreme Court is faced with a series of cases where a criminal defendant has alleged that his right to a fair and impartial jury was seriously compromised—a violation that should concern all Americans.

It’s worth emphasizing: The jury-trial right is critically important to our democratic structure because it’s the people’s way of exercising control over our third branch of government, the judiciary. As the Supreme Court has said, the impartial jury is a critical guard against the “arbitrary exercise of power” and “ensures the continued acceptance of the laws by all of the people.”

In recognition of how important the jury-trial right is to our democracy, close to 200 years ago, the Supreme Court said that it would guard against “every encroachment upon it … with great jealousy.” Unfortunately, the court has not always made good on that promise.

Last month, for example, the court denied a petition to review the case of Keith Tharpe, a black man who is on Georgia’s death row despite one of the jurors who sentenced him to death calling him a “nigger” who deserved to die. This same juror in that same sworn affidavit “wondered if black people even have souls.” As Justice Sonia Sotomayor recognized, Tharpe’s case is an “arresting demonstration that racism can and does seep into the jury system.” We should all be, to use Sotomayor’s words, “profoundly troubled” by the fact that Tharpe’s racially tainted death sentence still stands.

Also last month, the court held oral arguments in Flowers v. Mississippi. In that case, District Attorney Doug Evans had tried Curtis Flowers six times for the same crime. Over the course of the six trials, Evans used preemptory challenges to eliminate 46 of 49 black jurors. The persistent removal of black jurors is not only an injustice to Flowers, who is constitutionally entitled to an impartial jury, but also an affront to the dignity of the black citizens who reported to court to participate in a core function of our democratic process.

These cases prove, as Sotomayor said, that “the work of ‘purg[ing] racial prejudice from the administration of justice’ is far from done.” But our challenges are not limited to eradicating racial discrimination from the jury room. Anti-gay discrimination shows up there too.

Our challenges are not limited to eradicating racial discrimination from the jury room.

Next week, the court will consider whether to review the case of Charles Rhines. New evidence shows that at least one juror sentenced Rhines to death because he thought, as a gay man, he “shouldn’t be able to spend his life with men in prison.” One juror recalled another commenting that “we’d be sending him where he wants to go if we voted for [life without parole].” And a third juror confirmed that “there was lots of discussion of homosexuality. There was a lot of disgust. … There were lots of folks who were like, ‘Ew, I can’t believe that.’ ”

The NAACP Legal Defense Fund, where I am assistant counsel, has urged the court to grant Rhines’ petition because, like racial bias, anti-gay bias should not have a place in the jury box. South Dakota, where Rhines is on death row, is trying to trivialize these bigoted statements by pointing out that they’re examples of sexual-orientation discrimination as opposed to racial discrimination. But ultimately, that should be beside the point. The Constitution does not permit a person’s race to play any role in deciding whether they should be sentenced to die, and the court should hold that the Constitution does not permit a person’s sexual orientation to play a role either. Whether race or sexual orientation, the principle that Chief Justice John Roberts articulated in Buck v. Davis should remain the same: “Our law punishes people for what they do, not who they are.”

After the tragic decision to let Tharpe’s death sentence stand, we hope that the court meets its obligation to protect the right to a fair and impartial jury in the cases of Flowers and Rhines, because if discrimination in the jury box goes unchecked, a pillar of our democracy crumbles. As the Supreme Court has rightly observed, the impartial jury is “fundamental to our system of justice.” In accepting and deciding important cases that seek to remove state-sponsored discrimination from our jury system, the court must fulfill its singular power to keep the promises of our constitutional structure, ensure public confidence in our justice system, and foster respect for the rule of law.