Why corporate Dems hate Medicare For All

See Wendell Potter's interview here. An excerpt:

"Well, a lot of Democrats, the ones that I would refer to as corporate Democrats, those who take a lot of money still from corporate interests, including health care interests, they’re under the influence of the lobbyists for those companies, and have been persuaded by those lobbyists that private insurers have a legitimate role to play in our health care system. They’re getting big campaign checks. The Democratic Congressional Campaign Committee brings in a boatload of money from health insurance companies and health care providers, so they don’t want those checks to stop. So they are in many cases not favoring Medicare for All because insurance lobbyists don’t want that. They’re under some delusion that the insurance industry will be more favorably inclined to support some half measures; something that would, for example, create a public option, which is something that the insurance industry will fight just as fiercely as moving to Medicare for All."