One hundred and forty-four. That is the number of current openings in the federal judiciary. This amounts to 16 percent of our federal judgeships. In the next few years, President Trump and the Republican Senate will fill those seats with lifetime appointments. And with the aging of the judiciary, there could be as many as 438 vacancies by 2020.

The president has sought to fill these seats with young candidates, many of whom will serve on the courts for decades to come. In other words, the next generation of federal courts will be defined by the men and women whom Trump appoints to office.

It is easy to forget the critical role that federal judges play in our legal system. We tend to focus on the Constitution’s text and the men who wrote it, not on the judges who give it meaning. But the mere enumeration of rights in a Constitution is, in the words of James Madison, nothing more than a “parchment barrier.”

Instead, we must remind ourselves that the judiciary is the bulwark of our most fundamental rights, and many of the rights that we take for granted, from desegregated schools to the right to counsel, are in existence only because of how judges interpreted the open-ended language of the Constitution.

To protect these rights, and to ensure that the other two branches of government do not trample them, judges must be sufficiently independent to stand up to the president and to Congress. How can judges do that when it is the president and the Senate who decide who is going to serve on the courts?

Part of the protection is institutional: We the people gave judges life tenure so that they could decide cases without fear or favor. But that alone is not enough. We need our judges to be courageous, thoughtful and considerate. Because judges do so much more than merely call balls and strikes, the content of their character is much more important than the content of the Constitution itself.

Since one of the most important duties of a federal judge is to stand up to the other federal branches, it is important that the people serving on those courts are not mere lackeys for a partisan agenda. And that is where the people themselves must play a role.

We need to monitor closely whom our elected representatives place on the courts, and voice our concerns to our representatives. We must pay attention to who will serve as our protectors for the next 20, 30, even 40 years, and ensure that they are people we trust with that kind of responsibility. This is precisely why we should be outraged when the president attacks individual judges based on their national origin, questions their legitimacy or uses a litmus test to ensure that his nominees commit to decide constitutional cases a certain way.

It is easy to become complacent and assume that every judge will defend our rights. But we know that identity matters. Studies show that a judge’s ideology, religion, race and even the judge’s family can make a difference. For example, researchers have found that judges with daughters decide sex discrimination cases differently from those without. Scholars have likewise identified race-based and gender-based effects, along with many other potential influences on judicial decision-making.

That is exactly why judicial diversity is so important – and not just ethnic diversity or gender diversity, but also diversity of personal, political and life experiences. Unfortunately, this has not been a consideration for the president. Most of the president’s nominees have been white. Most of them have been male. Most have served as prosecutors or corporate lawyers. Lawyers with experience on the other side of the legal profession – civil rights lawyers, public defenders, advocates for minorities and the poor – have largely been ignored. This lack of diversity skews judicial decisions in favor of some interests and against others, and makes the quality of our judiciary poorer as a result.

Constitutional rights will not protect themselves. As someone who was born and raised in the former U.S.S.R., I have experienced this firsthand. The Soviet Constitution was filled with all kinds of rights and freedoms, all of which were ignored because no judge was willing to enforce them. We must ensure that our courts – the crown jewel of the American democracy – remain independent and willing to stand up for our constitutional rights. And more importantly, we must be vigilant to ensure that the courts are filled with those capable of ensuring equality and protecting the rights of all Americans.