According to a report in Politico, Donald Trump is considering using the Republican convention this summer to "announce his would-be Cabinet."
One problem: This would quite possibly be illegal under federal criminal law, an offense punishable by up to two years in prison:
Here is why Trump is not allowed to name Cabinet members before he is elected president: pic.twitter.com/yJs6xi3gsp— Sopan Deb (@SopanDeb) May 18, 2016
At least that's the conclusion the University of Miami's Michael Froomkin came to when this idea was floated for John Kerry in 2004. University of California, Irvine's Rick Hasen is less sure, noting that the federal statute requires the promise of appointment be made "for the purpose of procuring support in his candidacy." If Trump were only to promise jobs to people who'd already endorsed him, he might be able to use that in his defense.
Michael Matheson, a former researcher at the Congressional Research Service, notes that Trump could also try to distinguish a promise of an appointment from a promise of a job. He could say, "I only promised to send names to the Senate. That alone doesn't give anyone a job." Even so, Matheson concedes that candidates making such promises could be "in a bit of a tough spot legally" if prosecutors pressed the matter. Trump would have defenses available, but there's still a chance he'd lose.
It's worth noting that, if 18 USC § 599 really did prohibit shadow cabinets, that'd be a very dumb law. In countries with Westminster-style parliamentary systems — the UK, Canada, Australia, New Zealand, etc. — shadow cabinets are the norm, and are typically announced years in advance of an election. That process is simplified by the fact that their cabinets are usually exclusively made up of elected Parliament members, but it's still a good way to inform voters about who, precisely, will be governing them if the opposition party wins.
There's even some precedent for this in US history. In 1980, when Ronald Reagan and Gerald Ford were negotiating their idea for a "co-presidency," part of the deal was that Ford would be vice president but also get to pick Alan Greenspan as treasury secretary and Henry Kissinger as secretary of state. The deal fell through and George H.W. Bush was picked as Reagan's running-mate instead, but it'd be weird to think that Reagan and Ford would've been liable for prosecution had things gone another way.