I don’t think that follows really. There might be a case in preventing a state tax authority from turning returns over directly, perhaps because the federal government already has tax documents it should have access to. But once things are in the hands of a district attorney/law enforcement I don’t believe there’s anything barring the sharing of that evidence between Federal, State, and Local authorities. That sort of thing is pretty routine. And most routine FBI/DOJ investigations these days rely on a task force model that’s entirely based around doing so. Particularly once those tax returns get entered as evidence in a court room, they’re now a public record.
There isn’t neccisarily a jurisdictional problem at all. As a federal investigation wouldn’t neccisarily be looking into those state crimes. But federal ones, and looking to share evidence that pertains to that federal case. Which again is routine and happens every day.
But more importantly I don’t think there’s anyway the courts can block Congress from getting at them. Congressional investigations, particularly that whole impeachment thing, operate differently. And since NY State does not have an active interest in withholding anything from Congress. They’d likely just hand them over. I’m pretty sure state authorities have said they can and they will.
The cat would kinda be out of the bag with Trump filing suite over it after the fact, as a 3rd party. If they wanted to keep it in federal courts he might have pull with, they’d have to find something in federal law that blocks Congress from requesting or receiving state documents. I don’t think that something exists. And anything that might be based in State law… I don’t think NY’s elected supreme court justices are about to validate any of Trump’s crazy balls legal theories.
I think if these things make it to the Manhattan District Attorney, then Congress will have them in hand before Trump can do anything about it. At which point he’s making a mess trying to prevent them from using them in certain ways, while the details leak.
