Republicans do not want to "scrap" the ACA.
Because that means they would have to roll back the coverage for those with children up to age twenty-six. It also means they would have to roll back the coverage for those with pre-existing conditions. And they would have to put the "donut hole" back in for the seniors drug charges. They would have to go back to charging women more for the same coverage.
Also, they would have to tell all those folks on Medicaid thru Obamacare that they no longer are covered. And they would have to tell everyone that the Republican Party is happy with 40 million Americans uninsured - no opportunity to see a doctor and only the emergency room if they become ill.
They are not ready to tell the people that. Their hand is not as strong as they and their supporters might think. They have no choice but to help fix this problem. It is not acceptable to go back to the status quo. If they were to do otherwise, it is they that would suffer politically, not the President or the Democrats.