The Department of Justice threatens to arrest state officials if they count ballots from people the DOJ lists as potentially ineligible to vote. The district court concludes that the purported list is terrible and that the federal government has no authority here and enters a TRO enjoining the threats. The DOJ asks the Ninth Circuit for an immediate stay.
The panel draw is Chief Judge Murguia (an Obama appointee), Judge Callahan (a Bush appointee), and senior Judge Bea (a 92-year old Bush appointee). The two Republican appointees agree to stay the district court's order, and the Democratic appointee dissents.
The Ninth Circuit then pretty much immediately vote to take the case en banc and vacate the panel's opinion. No draw; every active judge gets a vote on that one.
But then there's another draw for the 11-member en banc panel. Chief Judge Murguia is automatically on it, and although Judge Bea is senior, so ordinarily wouldn't be eligible, since he was on the panel, his name goes into the hopper as well.
The ultimate draw: 6-5 in favor of Republican appointees. Including senior Judge Bea.
So, today, the en banc panel votes to reinstate the prior panel's opinion (and stay).
To reiterate: Luck of the draw. (Or, depending on your perspective, lack thereof.)