According to a brief filed in federal appeals court, AGs from Ohio and Montana are urging the court to throw out the ruling that declares the ACA unconstitutional. In doing this they are breaking with the Trump administration’s support of the ruling.
If appeals are not successful then the entire ACA will be struck down by the courts leaving congress scrambling to replace provisions like cost assistance and protections for pre-existing conditions.
Thus while the Republican led lawsuit is supported by some Republicans and the Trump administration, other Republicans like the AGs noted above think the ACA should stand.
Consider this passage from Politico:
Though the two attorneys general oppose the requirement to purchase coverage, they say they rest of the law should be allowed to stand, and they warn there could be negative consequences for millions of their residents if the judge’s decision is upheld.
“The fact that a ruling has negative consequences does not mean it is wrong,” write Dave Yost of Ohio and Timothy Fox of Montana. “Let justice be done, though the heavens may fall. But the District Court’s ruling is wrong, and its errors threaten harm to millions of people in the Buckeye and Treasure states.”
In short, while Republicans generally agreed that the mandate should go, not all Republicans agree that the popular provisions contained in the ACA should go, and thus not all agree that a full repeal by the court system is the best way forward.