The Democratic donors want someone like Gillibrand, Booker or Harris because they're scared someone more on the economic left will raise taxes and therefore would rather have an obsessive social issues candidate.
They all are advocating Medicare for all which will require massive tax increases to pay for considering we already aren't actually paying for our current Medicare program.
But Gillibrand, Booker, and Harris are somehow "centrists" even though no one outside of the Atlas bubble will see them as even remotely moderate on even economics. And they all have extremely liberal voting records.
I seriously don't understand why people think Medicare for all can be done with the click of a button. It's an extremely leftwing and expensive thing to pass. This isn't a small commitment.
If that were true, you wouldn't have places like the UK having it and Tories themselves not disputing it...not even at the height of Thatcher.
Also, similar things were said of Medicare/Medicaid in the '60's, and Social Security in the '30's.
Comparing US and the UK is dumb for obvious reasons. We're completely different countries.
FDR and LBJ only implemented those with huge 20% landslides and a massively lopsided democratic congress.
Sure, if the next democrat in 2020 wins by 20% and gets a massively lopsided democratic congress, they can do Medicare for all. Something tells me they will not win by 20%.