This is difficult to parse out, beyond simple polling data. The alternative on the table (ACHA, which I guess is actually off the table now) is FAR less popular. Polling on single payer
is mixed was well. Gallup puts support for it in the high 50s, but other polling outlets report overall support for it under 50%, and that support sometimes dips far below 50%.
In other words, we are far from any kind of popular consensus on health care. It's pretty disingenuous to say "the ACA is unpopular," because it's as well regarded a system as any which have been put on the table. Of course, the goalposts were moved to "popular" from "majority support" once it was pointed out that there are several measures of majority support for the ACA, but that was of course to be expected from our resident Kellyanne.