the attached link explains...not sure of all the details in the Twitter video man's circumstance, but as the link explains, the GOP, including Trump, have not found a good alternative for cancer survivors like him that is better than Obamacare...much less all the millions of others in this country who need and deserve affordable health care.
Link: https://www.vox.com/2017/2/23/14700634/cancer-obamacare-republican-repeal-replacement