Liz Warren is "with her," so she supports Hillary's "public option," which is a sham, designed to destroy Medicare. Clinton's "public option" would result in the sickest (most expensive) patients switching to Medicare coverage, draining Medicare funds. The healthier patients would stay with the private insurers.
The point of single-payer healthcare is the administrative savings, which are enormous, and the co-mingling of all participants, healthy and sick, so that the costs per participant are lowered. Clinton's plan is NOT single-payer, and will lower costs primarily for the insurance companies.
Read this and weep: "Destroying Medicare to Save ObamaCare: Hillary Clinton’s “Public Option” Plan" http://www.nakedcapitalism.com/2016/05/destroying-medicare-to-save-obamacare-hillary-clintons-public-option-plan.html
"In summary, Clinton’s attempt to save ObamaCare politically by adding on the “public option” is a bait and switch operation designed to eliminate the threat of Medicare for All. It worked that way in 2009, and Clinton’s pulling the same play out of the Democrat playbook for 2016. In, fact Clinton’s “public option,” despite her wonky reputation, is so skimpy on detail is to be insultingly unserious, exactly like the “public option” in 2009. The Democratic Establishment remains implacably opposed to Medicare for All, and if by some miracle they manage to pass the “public option,” that will undermine the existing Medicare program, which is no doubt their goal. On the life-and-death issue of providing health care to all Americans, there is more that divides us than unites us."