Has the 9th Circuit Court been overturned 80% of the time?

No. 0.12% of cases ruled on by the 9th circuit were overturned. 99.85% of cases were not heard by the Supreme Court. 0.03% of cases were confirmed by the Supreme Court.

In 99.88% of cases, the Supreme Court either wasn't brought in, chose not to take the case or approved of the 9th circuit's rulings.

This is from the data found by DavePhD. The total number of cases decided by the 9th circuit court of appeals was 114,199. Of that number, 107 were reversed, 33 were vacated, and 35 affirmed by the Supreme Court.

A total of 0.15% of 9th circuit cases were heard by the Supreme Court

Of those cases, 80% were overturned (reversed or vacated). This is the "Reversal Rate" and is the number they are using. The quote omits the fact that the "Reversal Rate", as understood by lawyers, does not include cases that weren't reviewed by the Supreme Court.

With data from Brythan (see their excellent answer), the Supreme Court sees approximately 7,000-8,000 writs of certiorari each term, only 80 of which they agree to take. Assuming the larger number for simplicity, that means 1% of cases requested for review are reviewed. Given that court reviewed 175 cases in the given time frame, we can extrapolate an approximate 17,500 cases were requested for review.

This would give an approximate breakdown of 84.7% of cases weren't even considered by the Supreme Court, 15.1% of cases were declined by the Supreme Court, 0.12% of cases were overturned, and 0.03% of cases were confirmed.

Therefore, the biggest deciding factor from a purely statistical point of view, is "Will the Supreme Court hear the case"? 99% odds they won't, even with a writ. If you hit that 1% odds, then you have 80% odds of the case being overturned. This assumes purely random decision making based on statistics.

But the case in question isn't going to be decided by statistics, but by judges making non-random decisions.

According to the American Bar Association article Supreme Court Reversal Rates: Evaluating the Federal Courts of Appeals:

The reversal rates in Figure 2 range between 55% and 84%. Interestingly, this comparison of reversal rates reveals that the Federal Circuit has the highest reversal rate at about 83.33%, and the Ninth Circuit has the second highest reversal rate at 80%. The Seventh Circuit has the lowest reversal rate at 55.26%. The median reversal rate is 68.29%.

The American Bar Association is defining "reversal rate" as (decisions reversed or vacated by the Supreme Court)/(decisions reversed, vacated, or affirmed by the Supreme Court).

In the time period of the bar association study (1999-2008), 114,199 cases were decided by the 9th circuit and 107 were reversed 33 vacated and 35 affirmed by the Supreme Court.

80% reversal rate does not mean that 80% of all the 9th circuit's decisions are reversed. For only about 1% of decisions is review by the Supreme Court requested by one of the parties, and of that 1% only a small fraction are heard by the Supreme Court.

The original question title asked:

Are 80% of Ninth Circuit judgements overturned by the Supreme Court?

No. Asked like that, the rate is between .1% and .2%.

The quoted claim is

The 9th Circuit Court has been overturned 80% of the time.

Which would be better stated as: of the cases from the 9th Circuit that have been reviewed by the Supreme Court, 80% are overturned. This is misleading in that many people will hear the first claim. The wording is overly ambiguous.

As @DavePhD posted the "overturn" rate statistic of 80% is correct. The problem is that not all cases are reviewed. So there might be a 114,199 cases, 175 are reviewed, and 140 are overturned. 140 is 80% of 175, but it is far less than 1% of the overall cases. That rate is between .1% and .2%.

USCourts.gov says:

In fact, the Court accepts 100-150 of the more than 7,000 cases that it is asked to review each year.

Obviously 150/7500 is only 2%. 80% of that would only be 1.6%. And of course, not every case is brought to the Supreme Court for Review. Numbers just for illustration -- the actual rate may differ somewhat.

The Supreme Court says:

The Court receives approximately 7,000-8,000 petitions for a writ of certiorari each Term. The Court grants and hears oral argument in about 80 cases.

It's not clear why the difference in numbers between the two sources. Regardless, the point is that the court does not hear most of the cases where review is requested, much less most of the cases issued by the circuits.

Note that in the context of the travel pause stay, it's not as misleading as it first seems. While only a small percentage of the overall judgments are overturned, a high percentage of those requiring review are overturned. This will almost certainly require review, as there is a conflict in the district courts of different circuits. A court in Seattle issued the stay while a court in Boston ruled the actions constitutional. The only way to resolve conflicts in different circuits is for the national court to rule. The Supreme Court is the national court. The term is circuit split.

The locution used in the quotes is skipping a step. In a random case, it's a big step. In this particular case, not quite as big. But 80% is still a high estimate at this point in the process.

As a side note, one of the reasons why the 9th Circuit has a high overturn rate is that it is too large for en banc review to proceed easily. So more litigants try to get a Supreme Court review without the step of en banc review. The 9th might have better statistics if it overturned some of its three judge panels itself, like the other circuits do. There have been some recent reforms that may help with that going forward, but that's unlikely to affect this particular case.

Yes. The cited claims are correct but the simplified/paraphrased post title is incorrect.

Both cited articles do qualify their respective "80% overturned" statements.

The first notes(with my emphasis):

If Trump brings makes his plea to the Supreme Court — with Justice Neil Gorsuch onboard — the “rogue” 9th Circuit decision will be overturned easily.

The second, quoting National Review, states:

The Ninth Circuit’s best showing in recent years was October Term 2009, with a 60 percent reversal rate in the 15 cases on which certiorari was granted.

I agree that someone not reading beyond the headlines might come to the mistaken conclusion that 80% of all of the 9th Circuit's decisions have been overturned, but we do not do that here, right?

The actual numbers aren't QUITE that bad.

9th Circuit record of case reversals by the Supreme Court: 2001-20% 2002-50% 2003-100% 2004-0% 2005-50% 2006-75% 2007-75% 2008-100% 2009-60% 2010-79% 2011-71% 2012-86% 2013-77% 2015-63%

Now those numbers represent just the cases from the 9th Circuit that were accepted by the Supreme Court. The majority of cases from any of the Circuit Courts aren't appealed to the Supreme Court. Of those that are appealed, most are rejected by the Supreme Court.

When the Supreme Court declines to hear an appeal, that is NOT a "tacit approval" as some like to claim (especially while trying to defend the 9th Circuit). The Supreme Court chooses which cases to hear based on a number of criteria which are not carved in stone (and not written in the law anywhere) but which are generally recognized as including things like the constitutional significance of the case and cases that represent conflicting rulings by different Circuit Courts.

The Supreme Court is rarely concerned about "Justice" per se - you could be on death row and bring an appeal to the Supreme Court based on proof you were innocent and the case would still be rejected if it didn't involve some issue of law (your innocence is NOT an issue of law). The Supreme Court picks cases that involve what the justices consider significant points of law.

So, yes, as some have pointed out, ALL the circuits have had cases reversed by SCOTUS, but yes, the 9th Circuit does have a pretty consistent reputation as the MOST overturned of all the Circuit Courts.