An almost always unanimous Supreme Court? We look at the data

By Prinz Magtulis
Aug. 11, 2025

How often does the Supreme Court reverse itself? That has been the question over the past week after the Senate decided to shelve impeachment proceedings against Vice President Sara Duterte after a unanimous ruling from the court that declared it unconstitutional.

Critics say the Senate's move was premature after the House of Representatives asked the court to reconsider its decision. But is it though? We look at the data.

At least for the most recent composition of the court, just before Raul Villanueva was named associate justice, an appeal hardly succeeded, much so when the ruling was unanimous. To be specific, our analysis of signed Supreme Court decisions from June 2022 to May 2025 – when there had been no change in the court's membership – found only five en banc decisions that were reversed, partially or fully, upon appeal.

Some cases where the en banc granted an appeal

Note: Data covers only signed decisions.

There is no available data on how many appeals are filed or pending with the court, so comparison to the total pie cannot be made. But five is a tiny fraction of the 227 signed decisions that the Supreme Court en banc, composed of the 15 justices, handed down in the three-year period covered by our analysis.

In total, the Supreme Court receives between 5,000 and 6,000 cases every year, according to government data. Not all are decided through a lengthy penned decision like in the case of Duterte's impeachment.

In fact, only about 5% of disposed cases had a signed decision last year, where the justices explained thoroughly the logic behind their ruling. Majority, it appears, are handed down through a single-page minute resolution containing a summary of the decision. These resolutions, whose share increased as of September last year, are not publicly available.

Just a fraction of court decisions get signed rulings

Share of penned decisions from January to September of each year

Others

Signed decisions

11%

2023

2024

Signed decisions

Others

11%

2023

2024

Signed decisions

Others

11%

2023

2024

Source: Author's analysis of Supreme Court data

However, as a small sample, the signed decisions provide a snapshot of how the justices vote and decide on cases, and there are some interesting findings. Foremost is that unanimity is very common at the Supreme Court. From June 2022 to May 2025, nearly 94% of signed decisions were decided by a unanimous vote. The share declines to 81.5%, albeit still elevated, if you only consider rulings by the en banc or the full court.

When the en banc is not handling a case, one of the three Supreme Court divisions does. Each division is composed of five voting justices, and it takes a simple majority to secure a ruling. Our analysis showed that almost always the five justices sitting in these divisions decide on cases unanimously.

That said, dissents do happen. About 6.3%, representing 77 penned decisions, recorded at least a justice disagreed with the majority ruling. At the en banc, the share of dissents goes up nearly three times to 18.5% of all signed decisions.

Among the justices, Senior Associate Justice Marvic Leonen has dissented the most in the court. Leonen dissented in 33 of 658 court decisions he deliberated on with his colleagues, representing 5% of the total rulings he helped hand down. He was followed by Associate Justices Amy Lazaro-Javier (3.4%) and Alfredo Benjamin Caguioa (3.1%).

If you just consider decisions handed by the en banc, Lazaro-Javier and Leonen are tied with 17 dissents.

Lazaro-Javier, Leonen are top dissenters

Dissenting votes in en banc decisions, by justice

Share of dissents in vote

Number of dissents

8.2%

Amy Lazaro-Javier

7.7%

Marvic Leonen

6.1%

Alfredo Caguioa

2.3%

Rodil Zalameda

2.1%

Ramon Paul Hernando

2.1%

Maria Filomena Singh

1.9%

Mario Lopez

1.9%

Samuel Gaerlan

1.5%

Ricardo Rosario

1.5%

Antonio Kho Jr.

1.4%

Jhosep Lopez

Alexander Gesmundo

1.0%

Jose Midas Marquez

0.9%

Japar Dimaampao

0.5%

Henri Jean Paul Inting

of dissents

Dissents

Amy Lazaro-Javier

8.2%

Marvic Leonen

7.7

Alfredo Caguioa

6.1

Rodil Zalameda

2.3

Ramon Paul Hernando

2.1

Maria Filomena Singh

Mario Lopez

1.9

Samuel Gaerlan

1.9

Ricardo Rosario

1.5

Antonio Kho Jr.

1.5

Jhosep Lopez

1.4

Alexander Gesmundo

1.0

Jose Midas Marquez

0.9

Japar Dimaampao

0.5

Henri Jean Paul Inting

0.5

Share of dissents

Dissents

Amy Lazaro-Javier

8.2%

Marvic Leonen

7.7%

Alfredo Caguioa

6.1%

Rodil Zalameda

2.3%

Ramon Paul Hernando

2.1%

Maria Filomena Singh

2.1%

Mario Lopez

1.9%

Samuel Gaerlan

1.9%

Ricardo Rosario

1.5%

Antonio Kho Jr.

1.5%

Jhosep Lopez

1.4%

Alexander Gesmundo

1.0%

Jose Midas Marquez

0.9%

Japar Dimaampao

0.5%

Henri Jean Paul Inting

0.5%

Among Leonen's notable dissents was in the August 2022 en banc decision that ruled that the loan secured by the Duterte administration to build the Chico River Pump Irrigation Project and New Centennial Water Source-Kaliwa Dam was valid. He was the lone dissenter in that case.

Interestingly, while Leonen dissented the most, he also seemed to be writing the most convincing decisions. He was the ponente or writer of 30 en banc decisions with no noted dissents, our analysis showed. The tally did not include his most recent ponencia in the vice president's impeachment case, which was also unanimous.

A 100% "concurrence rate" – computed as the number of signed en banc decisions with unanimous votes over the total signed rulings – was also recorded by Associate Justice Antonio Kho, Jr., although he wrote much fewer rulings. Closely following Leonen as top ponencia of en banc decisions was Associate Justice Henri Paul Inting with 27 written decisions and Associate Justice Maria Filomena Singh with 21.

All of Leonen's ponencia at the en banc secured unanimous votes from peers

Signed en banc decisions from June 2022 to May 2025, by ponente(author)

Ponencia with unanimous votes

Ponencia with dissenting votes

5 decisions

Marvic Leonen

Henri Jean Paul Inting

Rodil Zalameda

Maria Filomena Singh

Ramon Paul Hernando

Jhosep Lopez

Samuel Gaerlan

Japar Dimaampao

Ricardo Rosario

Antonio Kho Jr.

Mario Lopez

Alexander Gesmundo

Amy Lazaro-Javier

Alfredo Caguioa

Jose Midas Marquez

Ponencia with unanimous votes

Ponencia with dissenting votes

20 decisions

Marvic Leonen

Henri Jean Paul Inting

Rodil Zalameda

Maria Filomena Singh

Ramon Paul Hernando

Jhosep Lopez

Samuel Gaerlan

Japar Dimaampao

Ricardo Rosario

Antonio Kho Jr.

Mario Lopez

Alexander Gesmundo

Amy Lazaro-Javier

Alfredo Caguioa

Jose Midas Marquez

Ponencia with unanimous votes

Ponencia with dissenting votes

5 decisions

Marvic Leonen

Henri Jean Paul Inting

Rodil Zalameda

Maria Filomena Singh

Ramon Paul Hernando

Jhosep Lopez

Samuel Gaerlan

Japar Dimaampao

Ricardo Rosario

Antonio Kho Jr.

Mario Lopez

Alexander Gesmundo

Amy Lazaro-Javier

Alfredo Caguioa

Jose Midas Marquez

Note: Data counts only justices who participated and voted in the en banc session as indicated in court records. Therefore, unanimity is understood as all present justices agreeing to the decision.

While unanimity appears to be common, there were also contentious cases that divided the court. In our sample, we found two election cases where five justices dissented from the majority decision. The most recent case, decided last April, saw the court's majority siding with the Commission on Elections to disqualify Datu Pax Ali Mangudadatu, who won the gubernatorial race in Sultan Kudarat in 2022. Another case involves a contentious proclamation of a winning mayoral candidate in La Union.

There were also cases when the justices will concur with the result but dissent with the arguments of their colleagues. In these cases, their concurring vote was still counted, even as they typically offered alternative explanations for how they arrived to the same conclusions. Kho, Leonen, Caguioa and Lazaro-Javier had the most concurring and dissenting opinions, data shows.