Since the death of Justice Antonin Scalia, liberals as well as conservatives have appropriately paid tribute to his legacy as one of the most influential justices of the twentieth century. Commentators have noted Justice Elena Kagan’s generous tribute when she was Dean of Harvard Law School. “His views on textualism and originalism, his views on the role of judges in our society, on the practice of judging, have really transformed the terms of legal debate in this country,” she said. “He is the justice who has had the most important impact over the years on how we think and talk about law.” Describing Scalia’s influence in1997, the liberal political philosopher Ronald Dworkin more or less conceded, “We are all originalists now.”

Perhaps the greatest sign of Scalia’s influence is that liberal justices and scholars now make arguments about constitutional text and history, insisting that the conservative justices are ignoring the text and original understanding of the Constitution that Scalia insisted should be their guide. More than any justice since the liberal lion William Brennan, Scalia changed the way Americans debate the Constitution, and for that he deserves great respect.

At the same time, some commentators have noted a gap between Scalia’s influence on constitutional debate in general, and his influence within the Supreme Court in particular. Only one other justice—Clarence Thomas—is a card-carrying originalist. Because of his reluctance to compromise and build coalitions, Scalia’s most memorable opinions are his dissents. On the current Court, the most influential justice has been Anthony Kennedy, whose embraces a libertarian, natural-law based approach to constitutional interpretation entirely at odds with Scalia’s textualism and originalism.

As President Obama prepares to appoint a successor to Scalia, one lesson is clear: The most successful justices in the twentieth century—from Scalia to Brennan to Louis Brandeis—have left their mark on the law not as legalistic craftsmen but as constitutional visionaries. In other words; it’s not enough to embrace a purely political or a bloodlessly academic vision of constitutional interpretation; to succeed on the Court, you need to believe passionately in the constitutional values you are defending.

Whether you conclude that Scalia consistently embodied or betrayed his constitutional methodology of originalism, it’s clear that he distinguished himself as one of the few justices on the Court who had a clear constitutional methodology to betray. In 1993, fresh out of law school, I wrote to Scalia asking for an interview about his jurisprudence. He sent back the following, charming note:

Since being a judge, I have had a uniform policy of declining interviews for articles about me. That policy undoubtedly has its costs, but is in accord with our judicial tradition of avoiding publicity. (As you know, I am big on tradition.) It is tempting to make an exception for a piece of the rare sort you describe, but a rule is a rule. (I am also big on rules.) I am sorry to disappoint—and wish both of us good luck in your article.

In the article that emerged, brimming with youthful overconfidence, I argued that Scalia’s note was a perfect miniature of his jurisprudence. He emphasized the importance of separating his personal preferences from his jurisprudential conclusions, but concluded that he was bound by history, rules, and tradition to resist temptation. Scalia’s promise to separate his constitutional conclusions from his personal preferences was admirable, I suggested, but he sometimes failed to fulfill it, picking and choosing among the original text, history, and original understanding of the Constitution when they clashed with his firmly held policy views.

More than two decades later, it’s clear that the piece failed to give Scalia his due. It’s true that Scalia never confronted the sharpest challenges to his originalist jurisprudence—in particular, to the liberal originalist academics such as Akhil Amar of Yale Law School and litigators at groups like the Constitutional Accountability Center, who insisted that text and history, honestly interpreted, should lead to progressive as well as conservative results. Scalia never gave a satisfactory answer in public to why he thought Brown v. Board of Education was correctly decided, in light of the fact that leading conservative legal historians acknowledge that the framers and ratifiers of the 14th Amendment, in 1866 and 1868, did not intend to strike down school segregation. (When I asked Scalia the question point blank at a convivial dinner a few years ago, he replied, with a belly laugh, that no theory is perfect.) He also never engaged the extensive history of the original understanding of the 14th Amendment, suggesting that its framers and ratifiers intended to forbid not all racial classifications, as Scalia argued, but only those affecting civil rights, not political or social rights. This original understanding meant that Bush v. Gore was also impossible to justify on originalist grounds, since the framers of the 14th Amendment did not intend the equal-protection clause to apply to voting at all. Scalia brushed off this challenge, too, with the impatient, “Get over it!” (For a full bill of particulars against Scalia as an inconsistent originalist, see this review of his book, A Mattter of Interpretation, or pick up any law review published since his confirmation in 1986.)

It wasn’t only liberals who criticized Scalia as an inconsistent originalist; the libertarian scholar Randy Barnett called Scalia unfaithful to the original meaning of the Constitution in cases where he found the results too onerous and disruptive of existing institutions. (Scalia himself acknowledged the criticism, saying that he was less willing than Clarence Thomas to overturn every precedent inconsistent with original understanding because “I’m an originalist and a textualist, not a nut.”) More recently, however, Scalia repudiated his own self-described “faint-hearted originalism,” saying he would be willing to uphold laws requiring flogging, which he had previously questioned. In general, Scalia’s originalism because less nuanced as he grew older, leading him to insist that the most hotly contested constitutional questions were “easy” to resolve where he had previously acknowledged complexity.

At the same time, the case against Scalia as an inconsistent originalist fails to acknowledge the many occasions on which his constitutional conclusions did indeed diverge from his policy preferences. At an appearance at the Union League in Philadelphia a few months ago, he proudly pointed to his opinions holding that accused criminals have the right to confront their accusers, even though he had no fondness for the convicted rapist whose rights he defended. He also liked to invoke his vote to join a Supreme Court majority in defending the right of protesters to burn the American flag. “If it were up to me, I would put in jail every sandal-wearing, scruffy-bearded weirdo who burns the American flag,” Scalia said in his appearance at the Union League in November. “But I am not king.”

He struck down criminal statutes as too vague because they didn’t define the crime in question with sufficient specificity to give defendants notice of what conduct is prohibited. And, he wrote a series of magnificent opinions over the years voting to strike down overly intrusive searches – from GPS surveillance to DNA database searches to drug tests – on the grounds that they called to mind the hated general warrants and writs of assistance that the framers of the Fourth Amendment meant to prohibit. (For a fuller account of the decisions in which Scalia ruled for and against defendants, see this piece.).

A list of the cases where Justice Scalia ruled for defendants, however fails to convey the passion with which he defended constitutional values, and the indignation he unleashed on those who threatened them. In a 1989 dissent, he called drug tests by the Customs Service “a kind of immolation of privacy and human dignity in symbolic opposition to drug use.” And in his dissent from the Court’s decision to uphold the seizure of DNA samples from suspects on arrest, he wrote: “I doubt that the proud men who wrote the charter of our liberties would have been so eager to open their mouths for royal inspection.”

It was Scalia’s constitutional passion, in the end, that made him such a towering figure in 20th-century jurisprudence. His insistence that principled citizens should try to separate their personal convictions from their constitutional conclusions inspired a generation of young lawyers who did not always share his policy views—including me. And it also helped to reconcile the paradox that Scalia was both a justice who insisted on the need to separate his constitutional from his political conclusions and also a justice whose constitutional and political preferences often coincided.

A useful comparison here is Justice Louis Brandeis, who must be ranked, along with Scalia, among the most influential justices of the 20th century. (Brandeis, incidentally, was nominated on January 28 of the 1916 election year and confirmed on June 1, but President Wilson faced a Democratic Senate; Republican Senates have been less accommodating to lame ducks.) As I argue in the forthcoming Louis D. Brandeis, American Prophet,  Brandeis was lionized in his time for insisting on the need for judicial restraint, for separating his constitutional from his political conclusions, and for insisting that contested policy questions should be settled in legislatures rather than courts. In fact, however, for Brandeis, as for Scalia, the personal and constitutional generally converged: Brandeis, a ferocious opponent of the curse of bigness, in business and government, tended to uphold laws of which he approved on policy grounds and to strike down those he deplored.

For that reason, it’s not clear that either Brandeis or Scalia had a consistent commitment to judicial restraint that transcended their passionately held policy views. But both justices galvanized the nation, and transformed its constitutional debates, because of the clarity and power of their constitutional vision. Both believed in a few basic constitutional principles. For Brandeis, these principles included the importance of imposing limits on the size of business and government and of translating constitutional values of privacy and free speech in light of new technologies.

Scalia’s core principles included the importance of broad deference to unitary executive power (he was justly proud of his prescient and lone 1988 dissent from the Court’s 8-1 decision to uphold the ill-conceived Independent Counsel law, which eventually lapsed after the Clinton impeachment); of allowing states to enforce morality, in cases ranging from gay rights to abortion; of limiting government searches and protecting constitutional protections for defendants; and of ensuring that no branch of government infringed on the powers of the others. In this sense, although Brandeis was a Jeffersonian and Scalia a Hamiltonian, they were both constitutionalists who shared a commitment to limited government and the separation of powers. In choosing a successor to Scalia, Obama would do well to appoint a visionary constitutionalist in the tradition of Brandeis, who is willing to defend civil liberties and constitutional values from populist assaults on the left and the right.

Whether or not a Republican Senate will confirm any Obama nominee remains to be seen. But if Obama wants someone with the potential to influence the Constitution and the country as much as Justice Scalia did, he needs a nominee who has a clear constitutional vision and is willing to fight for it with as much zest and fervor as his distinguished predecessor. RIP Justice Scalia, who showed that only a passionate visionary can transform the terms of American constitutional debate. He will be missed.