When President Barack Obama took the oath of office, only one of the 13 federal courts of appeals had a majority of judges appointed by Democratic presidents. By the time he left office, the number had grown to nine.

Some of these courts have tilted decidedly leftward over the last eight years. Most famously, then-Senate majority leader Harry Reid exercised the “nuclear option” in 2013 to “pack” the powerful D.C. Circuit with three new appointees, increasing the likelihood that Obama’s progressive agenda would be upheld on that highly influential court.

Another example would be the Fourth Circuit, which “evolved” from a semi-reliably conservative court into one of the country’s most liberal courts during the Obama era. With its Democratically appointed judges outnumbering Republican-appointed judges by a two-to-one margin, the “new” Fourth Circuit struck down North Carolina’s voter identification law and sided with the Obama administration’s effort to force schools to allow students to use bathrooms consistent with their preferred gender identity. Most recently, it ruled against the Trump administration’s attempt to implement the so-called travel ban.

Conservatives were aghast at the transformation of the federal judiciary under President Obama. With the passing of Justice Antonin Scalia, their anxiety increased as they pondered the prospect of Hillary Clinton picking his replacement.

They were buoyed, however, when candidate Trump released his list of 21 prospective Supreme Court nominees, pledging to nominate Scalia’s replacement from that list. It was a brilliant and unprecedented maneuver. Trump correctly read the zeitgeist of—and appreciated the discomfort felt by—broad swathes of the electorate with respect to the future direction of the law and its monumental impact on society.

While many conservatives harbored doubts about Trump, they concluded that he could be trusted to nominate textualist and constitutionalist judges—those who would give full effect to the text of federal statutes as written and who would interpret the Constitution according to its original public meaning, rather than according to their own personal or political beliefs. It proved to be a turning point in the presidential campaign.

So far, President Trump has delivered on that promise, big time.

Upon settling into the Oval Office, Trump promptly nominated Neil Gorsuch to the Supreme Court. Gorsuch had served with distinction for over a decade on the Tenth Circuit Court of Appeals and was well-respected by his peers. His intelligence, impartiality, sense of fairness, grace, and humility were evident to anyone who watched his confirmation hearing. After a contentious battle in the Senate, Gorsuch was confirmed, and his impact on the Court is already being felt in cases involving religious liberty, statutory interpretation, national security, separation of powers, and the Second Amendment, and will continue to be felt for decades to come.

Another individual who was on the “Trump List,” Amul Thapar, has also been elevated. The Senate confirmed him to the Sixth Circuit in late May.

Including the Supreme Court, there are 890 authorized federal judgeships in the U.S. Currently, 137 are vacant. Another 23 federal judges have announced their intentions to retire in the near future, and even more vacancies are expected.

President Trump, ably assisted by White House Counsel Don McGahn, has already nominated 27 eminently qualified men and women to serve on the federal bench. Many of them were law clerks for distinguished jurists themselves before embarking on successful careers in private practice, public service, academia, or on the state bench. Each of these nominees couples practical experience and a keen intellect.

Filling these lower court vacancies with judges who understand that it is their duty to faithfully interpret—rather than make up—the law is critically important. The Supreme Court hears only about 75 cases a year. The federal courts of appeals, on the other hand, typically decide over 50,000 cases every year. District court judges consider hundreds of thousands of cases every year.

The public tends to focus, quite understandably, on the “big” cases decided by the Supreme Court. But the judicial buck usually stops in the lower courts, and the decisions made by lower court judges are likelier to have a far broader impact on lives and livelihoods of those who seek justice through the federal judicial system.

President Trump has an opportunity to reshape, slowly but surely, the direction of the law, and to leave his mark on the federal bench. Given the large number of vacancies that currently exist and the prospect of getting to nominate at least one more justice to the Supreme Court, this could be the defining feature and most lasting legacy of the Trump administration.