Shadow Cabinet is a non-starter in the US.
Parliamentary systems are forced into it because of the immediate change possible in PMs. Rivals within the party compete for ministries because their equivalent of Cabinet members are also legislators.
A Shadow Cabinet in US politics would quickly degenerate into public disputes within the party, and put too may restrictions and too much scrutiny on the ‘Shadow Secretaries’.
Well stated. Still, there’s nothing to prevent someone forming a ‘shadow’ government. If the DNC wanted to vet some of their members or anyone else as being ready to step in as cabinet secretaries, assuming they could be vetted by the Senate, no one would gainsay them their kabuki. One problem I see is that the Democratic bench is so thin, if not empty, they wouldn’t have enough players to form a scrum.
As long as no taxpayer money is involved, what do we care?