pre-existing conditions. the bill's co-sponsor also toeing the line. >> more people would have coverage and we protect those with pre-existing conditions. >> reporter: trump's defensiveness over the issue is understandable. the issue of whether the gop proposal maintains protections for all has been a central and toxic piece of the repeal debate for months. and one that has been magnified exponentially by, of all people, a late-night talk show host on a two-night attack. >> so last night on our show, i -- a senator from louisiana, bill cassidy. i took him to task for promising to my face that he would oppose any health care plan that allowed insurance people to turn people with pre-existing conditions away. and he said anything he supported would have to pass what he named the jimmy kimmel test. which was fine. it was good. but unfortunately and puzzlingly he proposed a bill that would allow states to do all the things he said he would not let them do. >> jimmy kimmel is joined by