Huh? She's not attacking Sanders on universal healthcare. She just disagrees with him on how to achieve universal healthcare.
By implying Sanders wants to "dismantle Obamacare" without saying that he wants to work toward a single-payer system in which more people rather than fewer people have access to healthcare, she implies (no doubt for political reasons) that Sanders wants to go back to a system in which more people are uninsured. In fact, the opposite is the case. That's disingenuous.
If we had a Canadian style system with all its long waiting lists and overcrowding, the people who are newly insured thanks to Obamacare would be worse off, not better.
Single payer can be done right, but Canada is not the model to base it on.