Making affordable health care available for people with low incomes costs money. It has to come from somewhere. The Affordable Care Act is financed by taxes. The Republican congress wants to eliminate those taxes, because they fall mostly on wealthy people. (There are some additional levies on insurance and pharmaceutical companies that pay for parts of the act that are really side issues.) But they also know they will pay a political price for eliminating health insurance for millions of people, and specifically for sick people who really need it.
There is no way to square this circle. But most citizens don't understand this basic fact. Many of them don't even know that Obamacare and the Affordable Care Act are the same thing. And:
[O]nly 61 percent of adults knew that many people would lose coverage through Medicaid or subsidies for private health insurance if the A.C.A. were repealed and no replacement enacted. In contrast, approximately one in six Americans, or 16 percent, said that “coverage through Medicaid and subsidies that help people buy private health insurance would not be affected” by repeal, and 23 percent did not know.
It's no wonder that no legislation has moved yet in the Congress. There is no alternative to the ACA that won't kick millions of people off of the insurance roles, make insurance worse for most other people, and won't require taxes. Therefore the Republicans will never be able to do what they have promised to do.
What will they do instead?