In the span of two days, the U.S. Supreme Court upheld Obamacare and legalized same-sex marriage nationwide. While these decisions signal a liberal shift, the Court is still ideologically divided. In fact, some of the most conservative justices in modern U.S. history sit on the Supreme Court today.

Using data from Segal and Cover, InsideGov ranked the 15 most conservative SCOTUS Justices of the modern era (FDR to Obama). Justices are scored on a scale of 0 to 100, where 0 represents most conservative and 100 is most liberal.

Remarkably, six of the nine current SCOTUS justices made the list. Do the recent liberal rulings signal a new direction for the Court? Or will a stronger conservative ideology resurface?

*Note: Segal and Cover measure the “perceived” ideology of each justice by analyzing pre-confirmation newspaper editorials regarding the nominations.

The Centrists

Supreme Court Justices | InsideGov

Score: 50

  • Tom C. Clark
  • Charles E. Whittaker
  • Byron R. White

With a score of 50, these three justices are neither true conservatives nor liberals. Instead, they held moderate views on most issues, which made them important swing votes in many cases.

Stephen G. Breyer

Justice Stephen G. Breyer – Ideology | InsideGov

Score: 47

One of the current justices, Breyer has been defined by his moderate views. Although he has historically voted liberal in civil rights and union cases (he voted in favor of same-sex marriage), Breyer leans more conservative when it comes to economic cases and First Amendment issues. Justice Breyer was appointed by President Clinton in 1994.

Sandra Day O’Connor

Justice Sandra Day O’Connor – Ideology | InsideGov

Score: 41

President Reagan made history when he nominated Sandra Day O’Connor—the first woman to be appointed to the Court. Over her 25 years in the position, Justice O’Connor frequently voted with the court’s conservative bloc. However, as her views became more moderate, she became an important swing voter.

Anthony Kennedy

Justice Anthony McLeod Kennedy – Ideology | InsideGov

Score: 36

As the current swing vote of the Supreme Court, Justice Kennedy is undoubtedly one of the most influential people in America. On many of the court’s 5-4 decisions—including the same-sex marriage ruling—Kennedy has been the deciding vote. Although the majority of his votes have been with the conservative bloc, he has gradually become more liberal.

James Francis Byrnes

Justice James Francis Byrnes – Ideology | InsideGov

Score: 33

Despite being appointed to the court by Franklin D. Roosevelt, Byrnes was actually fairly conservative. Justice Byrnes didn’t have time to make much of an impact though, as he resigned from the court after just one year—the shortest tenure of any Supreme Court justice.

David H. Souter

Justice David H. Souter – Ideology | InsideGov

Score: 32

When George H. W. Bush appointed David Souter to the court, he was expecting to get a staunchly conservative justice. While Justice Souter initially delivered on that promise, he quickly became one of the more liberal justices in the court. Conservatives were less than pleased with the outcome. Given Segal and Cover’s methodology, Souter certainly ranks more conservatively than his rulings would indicate.

Harold Hitz Burton

Justice Harold Hitz Burton – Ideology | InsideGov

Score: 28

Although Justice Burton was a reliably conservative vote in the court, he did swing left on certain cases. Most notably, Burton played an important role in Brown v. Board of Education (1954), when he argued that segregation of public schools was unconstitutional.

John Paul Stevens

Justice John Paul Stevens – Ideology | InsideGov

Score: 25

John Paul Stevens was one of the longest-serving justices in history, holding office for 35 years. Like Justice Souter, Stevens’ ideology shifted from conservative to more liberal over his long tenure. Even so, Stevens was still an important conservative vote in several landmark cases. For example, he voted to reinstate the death penalty in Gregg v. Georgia (1976).

Lewis Franklin Powell Jr.

Justice Lewis Franklin Powell Jr. – Ideology | InsideGov

Score: 16-tie

Powell came from a background in corporate law and staunchly supported free-market capitalism during his tenure as Supreme Court Justice. Powell is one of the four Nixon-appointees to make this list.

Clarence Thomas

Justice Clarence Thomas – Ideology | InsideGov

Score: 16-tie

One of the most conservative justices on the Supreme Court today, Thomas is also the quietest member. In fact, he went nearly seven years without speaking a word in the courtroom. Though he may not say much, Thomas has written sharply conservative opinions. He is especially conservative when it comes to civil rights issues and he opposed same-sex marriage.

John Roberts Jr.

Justice John G. Roberts Jr. – Ideology | InsideGov

Score: 12

With his support of Obamacare in the 2015 ruling, current Chief Justice John Roberts Jr. outraged the conservative community. This was the second time Chief Justice Roberts upheld the Affordable Care Act. Republicans shouldn’t forget Roberts’ other rulings, though.The Chief Justice is generally aligned with the other conservative justices and has been consistently conservative over first amendment and economic issues.

Harry Andrew Blackmum

Justice Harry Andrew Blackmun – Ideology | InsideGov

Score: 11-tie

Another Nixon appointee, Blackmun started his Supreme Court tenure as a solidly conservative justice, supporting capital punishment and free-market economics. With Roe v. Wade (1973), Blackmun made a radical shift from his conservative ideology, voicing his support for women’s abortion rights.

Warren Earl Burger

Justice Warren Earl Burger – Ideology | InsideGov

Score: 11-tie

Chief Justice Warren Earl Burger—not to be confused with Chief Justice Earl Warren—remained largely conservative throughout his entire tenure. A Nixon-appointee himself, Burger presided over the court during the landmark United States v. Nixon (1974) case and delivered the final opinion. The court unanimously ruled against Nixon, declaring that not even the U.S. president is above the law.

Samuel Alito Jr.

Justice Samuel A. Alito Jr. – Ideology | InsideGov

Score: 10

Alito is one of the few Supreme Court Justices who has become more conservative over time. He has consistently voted with the conservative bloc of the Supreme Court and recently opposed the Obamacare and same-sex marriage rulings. Alito is also one of the youngest justices in the Supreme Court right now.

William Hubbs Rehnquist

Justice William Hubbs Rehnquist – Ideology | InsideGov

Score: 4

Rehnquist was one of the longest-serving Chief Justices in U.S. history. He was at the head of a strong conservative bloc in the Court during the 1980s and framed a series of conservative rulings on capital punishment, abortion, and affirmative action. He also played a pivotal role in Bush v. Gore (2000), effectively ending the presidential election and instating George W. Bush as president.

Antonin Scalia

Justice Antonin Scalia – Ideology | InsideGov

Score: 0

With 28 years on the job, Antonin Scalia is currently the longest-serving justice in the Supreme Court. He is also the most conservative. In fact, few justices have ever been so consistently conservative throughout their Supreme Court tenure. Scalia is known for writing his own separate opinions in many cases and holds no punches when he disagrees with the Court’s ruling.

Ideology Over Time

The graphic below shows the change in each conservative justice’s ideology over time. Negative scores represent liberal ideology and positive scores represent conservative ideology. It’s interesting to note that many of these justices shifted toward a more liberal stance over time. Justices Stevens, Blackmun, and Souter had particularly dramatic changes in ideology.

Conservative Supreme Court Justices Ideology Over Time | InsideGov

Compare SCOTUS Justices On InsideGov

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