If enacted, the Congressional Budget Office estimates over the next 10 years the American Health Care Act will cut $880 billion in federal funds from Medicaid. These cuts would leave up to 24 million people without health insurance over the same time period.
Under the Affordable Care Act, Medicaid expanded coverage to around 11 million people.
http://www.vox.com/2017/3/13/14914812/trump-ahca-medicaid-cuts
http://www.nola.com/politics/index.ssf/2017/03/mitch_landrieu_trump_blatantly_1.html
Mr. Trump ran promising repeal and replace the Affordable Car Act with something better. He also promised not to make cuts to Medicaid or Social Security. The American Health Care Act breaks both these promises.