The ACA is a center right to right leaning policy. It’s a middle ground between Medicare for All and the disaster that privatized healthcare was before the ACA.
Republicans are in a lose-lose position because they cornered themselves into rabidly opposing anything Obama did and calling it communism. Obama tried to appeal to moderates and republicans by making the ACA an incredibly bipartisan approach to healthcare. The republicans didn’t want to let Obama have a win so the party threw everything they could behind blocking it in the hopes that when they won next they would copy it and change a few minor things and pass it off as some completely new idea nobody had ever considered.
Notice that when Trump was in office, the proposed healthcare bill (AHCA) the republicans put together was just a slightly tweak of the ACA. Then they canned it when it was wildly unpopular, shrugged and moved on. Now the doublespeak is “Obamacare was bad but it would’ve been worse if it hadn’t been for me and we’re gonna fix it, but don’t ask me how yet.”
And that’s the best they’ve come up with in the 14 years since the ACA was passed.