I'm not so sure.
I think a huge number of Democratic voters would be just as susceptible to voting for a famous person based on their personality rather than a record of policy positions.
I reckon that someone with cross-political appeal and a big enough name would run away with the nomination just as Trump did.
The Rock, Tom Hanks, Oprah Winfrey, Bruce Springsteen. If any of those really fancied it then I reckon they'd get the nomination and would probably win the election as well.
But then I approach this from a positon of usually being wrong as well.