Sen. John McCain (R-Ariz.) and Sen. Lindsey Graham (R-S.C.) chat on an escalator on Capitol Hill in Washington, Feb. 15, 2017. The two senators have long been friends and collaborators, but the bond is being tested by how McCain will vote on he so-called Graham-Cassidy bill, which would dismantle the Affordable Care Act by taking money spent under the law and sending it to states in the form of block grants. Al Drago/The New York Times