The Affordable Care Act (Obamacare)

Please, someone help me understand how Ted Cruz or any other GOP candidate could rescind the Affordable Care Act (Obama Care) without giving specific alternate plans?   What do we do with the 16 million people now insured under the ACA who were not insured before the ACA was enacted?

Honestly, I now that many have had to face hefty challenges both financially and in keeping primary doctors.  But doesn’t the fact that 16 million more Americans have access to insurance worth some of the pain (and expense) from those of us who have always had health insurance?   The ACA, in my opinion, levels the playing field between those who can afford insurance and those who have always had access to health care.  If there is a better plan, we need to know about it!