Obama sucked at his job. Like, nearly Carter-level blindness to political reality, but with more personal arrogance. Obama was better than Shrub. Shrub was a war criminal, so you'd have to hope Obama was better.
The ACA was emblematic of Obama's unwillingness to lift a finger to help build the Democratic grassroots. The Democrats in Congress allowed the ACA to be loaded with poison pills due to Obama's insistence on a bipartisan vote. The result: no votes from the Gops, but it did cause the Democrats to lose the House since -- due to the Gop amendments -- the good parts didn't kick in until well after the midterm elections and the bad parts started immediately.
So popular was the ACA, in the end, that it only survived the Trump years because McCain lost his temper on the day of the Senate vote to repeal it.