Thats why i said it is "slightly left". everyone left wing will agree with you that a single payer health care system would be preferable to the status quo.
I do not see the moderates/right wing advocating for universal health care in the US, because the establishment does not give a fuck about the health of the common people. Therefore this is a left-wing position in the US, while it might not be an identifier for being left wing in other nations.