How Does the Supreme Court Lean?
Where each justice sits on a liberal–conservative scale, every term since 1937. One seat can tip the Court’s majority, so who holds it, who appointed them and how far they drift shapes how the country’s biggest cases come out.
How to read this
Martin–Quinn scores estimate each justice’s ideology from how they vote in divided cases: justices who vote alike land close together, and a justice’s position can move from one term to the next. The data run from the 1937 term through the 2024 term. Pick a term to see who sat on the Court and which presidents appointed them.
Where the justices stand
From the 1990 term through the 2024 term, the justice most likely to be the Court’s median, its middle vote, was a Republican appointee every term. From 1937 through 1989 it was a Democratic appointee in 44 of 53 terms.
- Most liberal
- Sotomayor
- Median
- Kavanaugh
- Most conservative
- Thomas
Data notes
The Court in the selected term, liberal to conservative, left to right; dot color is the party of the president who appointed each justice, and clicking a justice opens their profile. The median is the justice most likely to cast the middle vote, an estimate with a probability, not a certainty. Martin–Quinn scores sit on one liberal–conservative scale and are not comparable in number to the DW-NOMINATE scores on the Congress pages. Hollow dots mark justices who left or joined mid-term; in 1937, 1938, 1956 and 2005, where MQ scores two records, the median is the Court after the change.
View as table
| Justice | Appointed by | Party | Score |
|---|---|---|---|
| Sonia Sotomayor | Obama | Democratic | −4.19 |
| Ketanji Jackson | Biden | Democratic | −2.81 |
| Elena Kagan | Obama | Democratic | −1.84 |
| John Roberts | G.W. Bush | Republican | 0.33 |
| Amy Barrett | Trump | Republican | 0.52 |
| Brett Kavanaugh | Trump | Republican | 0.55 |
| Neil Gorsuch | Trump | Republican | 1.08 |
| Samuel Alito | G.W. Bush | Republican | 2.50 |
| Clarence Thomas | G.H.W. Bush | Republican | 3.07 |
Who each president appointed
Nine Democratic appointees, most recently White in 1962, have conservative career averages, and six Republican appointees, most recently Souter in 1990, liberal ones. All 11 justices appointed from 1991 through 2022 average on their appointing party’s side: Republican conservative, Democratic liberal.
Data notes
Career average for every justice a president put on the Court, the mean of the justice’s per-term scores, so it can hide justices who moved a long way; a ring marks justices sitting in the selected term. Justices still serving are not final.
View as table
| President | Justice | Career average | Scored terms |
|---|---|---|---|
| Biden | Ketanji Jackson | −2.62 | 2022–2024 |
| Trump | Neil Gorsuch | 1.04 | 2016–2024 |
| Trump | Brett Kavanaugh | 0.56 | 2018–2024 |
| Trump | Amy Barrett | 0.77 | 2020–2024 |
| Obama | Sonia Sotomayor | −3.27 | 2009–2024 |
| Obama | Elena Kagan | −1.74 | 2010–2024 |
| G.W. Bush | John Roberts | 0.81 | 2005–2024 |
| G.W. Bush | Samuel Alito | 2.00 | 2005–2024 |
| Clinton | Ruth Ginsburg | −1.76 | 1993–2019 |
| Clinton | Stephen Breyer | −1.32 | 1994–2021 |
| G.H.W. Bush | David Souter | −0.77 | 1990–2008 |
| G.H.W. Bush | Clarence Thomas | 3.40 | 1991–2024 |
| Reagan | Sandra O'Connor | 1.02 | 1981–2005 |
| Reagan | Antonin Scalia | 2.50 | 1986–2015 |
| Reagan | Anthony Kennedy | 0.68 | 1987–2017 |
| Ford | John Stevens | −1.81 | 1975–2009 |
| Nixon | Warren Burger | 1.89 | 1969–1985 |
| Nixon | Harry Blackmun | −0.03 | 1969–1993 |
| Nixon | Lewis Powell | 0.97 | 1971–1986 |
| Nixon | William Rehnquist | 2.97 | 1971–2004 |
| Johnson | Abe Fortas | −1.32 | 1965–1968 |
| Johnson | Thurgood Marshall | −2.82 | 1967–1990 |
| Kennedy | Byron White | 0.44 | 1961–1992 |
| Kennedy | Arthur Goldberg | −1.07 | 1962–1964 |
| Eisenhower | Earl Warren | −1.26 | 1953–1968 |
| Eisenhower | John Harlan | 1.62 | 1954–1970 |
| Eisenhower | William Brennan | −1.78 | 1956–1989 |
| Eisenhower | Charles Whittaker | 1.17 | 1956–1961 |
| Eisenhower | Potter Stewart | 0.40 | 1958–1980 |
| Truman | Harold Burton | 1.00 | 1945–1958 |
| Truman | Frederick Vinson | 1.03 | 1946–1952 |
| Truman | Tom Clark | 0.47 | 1949–1966 |
| Truman | Sherman Minton | 1.10 | 1949–1956 |
| F. Roosevelt | Hugo Black | −1.76 | 1937–1970 |
| F. Roosevelt | Stanley Reed | 0.37 | 1937–1956 |
| F. Roosevelt | Felix Frankfurter | 0.52 | 1938–1961 |
| F. Roosevelt | William Douglas | −4.70 | 1938–1975 |
| F. Roosevelt | Frank Murphy | −1.59 | 1939–1948 |
| F. Roosevelt | James Byrnes | −0.18 | 1941–1941 |
| F. Roosevelt | Robert Jackson | 0.70 | 1941–1953 |
| F. Roosevelt | Wiley Rutledge | −1.42 | 1942–1948 |
| Hoover | Charles Hughes | 0.19 | 1937–1940 |
| Hoover | Owen Roberts | 1.52 | 1937–1944 |
| Hoover | Benjamin Cardozo | −1.59 | 1937–1937 |
| Coolidge | Harlan Stone | 0.01 | 1937–1945 |
| Harding | George Sutherland | 1.60 | 1937–1937 |
| Harding | Pierce Butler | 2.23 | 1937–1938 |
| Wilson | James McReynolds | 3.50 | 1937–1940 |
| Wilson | Louis Brandeis | −0.61 | 1937–1938 |
How each justice moved
The Court median was lowest in the 1963 term (−1.13) and highest in 1988 (1.10); from 1969 through 2024 it fell below zero only in 2014, 2015 and 2016. Blackmun went from 1.63 in the 1971 term to −1.93 in 1993.
Data notes
Every justice’s score, term by term, from 1937 through 2024, with the Court median in bold; click or drag to change the term, and click a line to open that justice’s profile. Martin and Quinn estimate each score from the justice’s votes in non-unanimous cases; it is an estimate with a 95% interval, not a measured position, and the model lets scores drift from term to term, so a justice’s stability is partly an assumption.
View as table
| Term | Court median |
|---|---|
| 1937–1938 | −0.56 |
| 1938–1939 | −0.68 |
| 1939–1940 | −1.00 |
| 1940–1941 | −0.63 |
| 1941–1942 | −0.14 |
| 1942–1943 | 0.10 |
| 1943–1944 | 0.04 |
| 1944–1945 | −0.09 |
| 1945–1946 | 0.07 |
| 1946–1947 | 0.24 |
| 1947–1948 | 0.44 |
| 1948–1949 | 0.55 |
| 1949–1950 | 0.87 |
| 1950–1951 | 0.92 |
| 1951–1952 | 0.93 |
| 1952–1953 | 1.06 |
| 1953–1954 | 0.58 |
| 1954–1955 | 0.35 |
| 1955–1956 | 0.56 |
| 1956–1957 | 0.16 |
| 1957–1958 | 0.58 |
| 1958–1959 | 0.64 |
| 1959–1960 | 0.34 |
| 1960–1961 | 0.45 |
| 1961–1962 | −0.04 |
| 1962–1963 | −1.07 |
| 1963–1964 | −1.13 |
| 1964–1965 | −0.70 |
| 1965–1966 | −0.56 |
| 1966–1967 | −0.41 |
| 1967–1968 | −1.04 |
| 1968–1969 | −0.89 |
| 1969–1970 | 0.19 |
| 1970–1971 | 0.38 |
| 1971–1972 | 0.64 |
| 1972–1973 | 0.94 |
| 1973–1974 | 0.61 |
| 1974–1975 | 0.62 |
| 1975–1976 | 0.49 |
| 1976–1977 | 0.47 |
| 1977–1978 | 0.23 |
| 1978–1979 | 0.16 |
| 1979–1980 | 0.24 |
| 1980–1981 | 0.23 |
| 1981–1982 | 0.27 |
| 1982–1983 | 0.67 |
| 1983–1984 | 0.88 |
| 1984–1985 | 0.83 |
| 1985–1986 | 0.93 |
| 1986–1987 | 0.88 |
| 1987–1988 | 0.98 |
| 1988–1989 | 1.10 |
| 1989–1990 | 0.88 |
| 1990–1991 | 0.93 |
| 1991–1992 | 0.76 |
| 1992–1993 | 0.83 |
| 1993–1994 | 0.82 |
| 1994–1995 | 0.74 |
| 1995–1996 | 0.69 |
| 1996–1997 | 0.78 |
| 1997–1998 | 0.79 |
| 1998–1999 | 0.85 |
| 1999–2000 | 0.84 |
| 2000–2001 | 0.58 |
| 2001–2002 | 0.37 |
| 2002–2003 | 0.27 |
| 2003–2004 | 0.23 |
| 2004–2005 | 0.11 |
| 2005–2006 | 0.50 |
| 2006–2007 | 0.45 |
| 2007–2008 | 0.41 |
| 2008–2009 | 0.58 |
| 2009–2010 | 0.51 |
| 2010–2011 | 0.58 |
| 2011–2012 | 0.29 |
| 2012–2013 | 0.24 |
| 2013–2014 | 0.07 |
| 2014–2015 | −0.23 |
| 2015–2016 | −0.27 |
| 2016–2017 | −0.06 |
| 2017–2018 | 0.29 |
| 2018–2019 | 0.36 |
| 2019–2020 | 0.30 |
| 2020–2021 | 0.63 |
| 2021–2022 | 0.67 |
| 2022–2023 | 0.52 |
| 2023–2024 | 0.51 |
| 2024–2025 | 0.46 |
Source: Martin, Andrew D. and Kevin M. Quinn. 2002. “Dynamic Ideal Point Estimation via Markov Chain Monte Carlo for the U.S. Supreme Court, 1953–1999.” Political Analysis 10:134–153. Scores from mqscores.wustl.edu.
Appointing president and party from the Federal Judicial Center biographical directory.