They already are required to cover pre-existing conditions by the ACA. This is a bold-faced attempt by Republicans to continue undermining the ACA instead of working to improve it. Improve the ACA. Go to single-payer if you have to. But don't rot the ACA from the inside out or you will be known for trying to hoodwink the American people and blood will be on your hands when people die due to lack of adequate coverage that you took away by dismantling the ACA.