That event is the all-caps BRIDGEGATE in Katz's tweet -- the Watergate-inspired shorthand for the bridge closure and its subsequent cover-up, of which no link to Christie has ever been shown.
Federal prosecutors investigating the closure have charged two state officials in the incident, and a third pleaded guilty. During that case, a list of "unindicted co-conspirators" was developed -- people who are alleged to have participated in a conspiracy but who aren't part of the indictment at hand. (As ABC News explains, that can be because there's insufficient evidence or because the conspirators are cooperating with the prosecutors.) Media organizations sued for the release of that list in an attempt to learn who else knew about the plan, and a judge ordered that it be made public last week. One of the people on the list, though, sued to keep it private, and so the matter came to the Third Circuit Court of Appeals in Philadelphia. (For obvious reasons, that person's identity isn't known.)
This is where we fold in Donald Trump. At one point in time, Trump and Christie were competing for the Republican nomination, but after Christie dropped out, he joined Trump's team. He's been out on the campaign trail in support of the businessman, and in exchange, he has been named to lead a possible transition team for President-elect Trump (should that ever be his title). Trump also agreed to hold an event for Christie in New Jersey to help the governor retire his campaign debt (though it doesn't seem to be a hot ticket). In other words, the two are, at this point, pretty tight.
Hence Katz's marvelling at the twists of fate in the unindicted co-conspirators list. One of the judges on the Third Circuit, one of the judges who might be asked on June 6 -- the day before the New Jersey primary -- to hear oral arguments about the potential release of the the list, is Judge Maryanne Barry. Bary's full name is Maryanne Trump Barry. She is Donald Trump's sister.
What's the likelihood of Barry actually being impaneled to hear the case? We spoke with professor Daniel Richman of the Columbia University Law School, who explained how it works.
The Third Circuit hears appeals cases from Pennsylvania, New Jersey, Delaware and the Virgin Islands, meaning that it has jurisdiction in the current case. Federal circuit courts of appeals have rotating three-member panels that hear cases over a set time period. (The Third Circuit has nearly 30 judges.) The schedule for who is set to hear cases the first week of June is likely already set, Richman said, meaning that Barry could already be scheduled to hear cases at that point.
Which doesn't mean that she would actually be involved in the Bridgegate decision-making. It's likely it's not as easy as Barry switching weeks with another judge. "I would assume it's more formal than that. Normally these things are set in advance, and case-specific changes would not be done will-nilly, haphazardly," Richman said. "It's usually done through the combination of the clerk's office and the chief judge." If she is scheduled for that week, she can probably could recuse herself, leaving a two-person panel to decide the case.
Then there's the last capped word in Katz's tweet: SECRET. Another determination that needs to be made before June 6, as reported by WNYC, is whether or not the proceedings on that date will be held in secret. The central argument offered by the person on the list who wants to keep it private is that he or she would be assumed to have committed criminal acts if the list is made public; keeping the hearing secret would allow that person's attorneys to maintain his or her privacy as the case is debated.
What Katz is marvelling over isn't the idea that there's somehow something untoward about the fact that Trump's sister might be weighing in on this thing. It's that this weird election cycle insists, constantly, on being weirder.