Democrats fighting for their party's presidential nomination have been advocating ways to expand health-insurance coverage, such as Medicare for All and Medicare for All [Who Want It]. Over at Five-Thirty-Eight, Dan Hopkins looks at what the history of public-opinion polling on the Affordable Care Act (aka Obamacare) might mean for the Democrats' new Medicare-based proposals.
I do feel the headline's allusion to "Obamacare's Unpopularity..." may be misleading. The article itself nicely contextualizes the matter, arguing the the overall ACA has been less popular than would be expected from the high popularity of many of the law's provisions. Hopkins also notes that even the overall ACA has been above-water (approval greater than disapproval) since the time Trump took office. My point is simply that Obamacare has not been "unpopular" in an absolute sense in recent years.