(Senate Television via AP) In this image from video provided by Senate Television, Sen. John McCain, R-Ariz. speaks the floor of the Senate on Capitol Hill in Washington, Tuesday, July 25, 2017. At 1:29 a.m. on July 28, McCain strode onto the Senate floor. The 80-year-old, just weeks after a diagnosis of aggressive brain cancer, was poised to cast the tiebreaker vote on the GOP’s health care bill, in what was meant to be the fulfillment of seven years of work to undo President Barack Obama’s signature health care law. McCain paused for a moment, and then gave the measure a thumbs-down.