My take is that this is typical McCain, who has one of the most consistent conservative and Republican Party-line voting records in the Senate, gave us another example of his long performance as the Serious Conservative who expresses deeply concerned about the sad lack of bipartisan accord and then votes the hardline Republican position.
It also has a stock appeal to bipartisan cooperation, meaning the Democrats should agree to what the Republicans want. But the Maverick's many doting admirers in the press corps happily processes this as high-minded statesmanship.
The Young Turks shared their early reactions on Tuesday, John McCain Makes Epic "No" Trumpcare Speech, Votes Yes 07/25/2017:
Charlie Pierce weighs in (The Price of John McCain's Republican Loyalty Esquire Politics Blog 07/25/2017):
It was an ugly day in the United States Senate on Tuesday, as ugly a day as has been seen in that chamber since the death of Strom Thurmond, who used to make a day ugly simply by showing up. The Senate took up the Motion To Proceed on whatever the hell hash Mitch McConnell wants to make out of the American healthcare system. (The decision now seems to be between whether we kick 30 million, 22 million, or 18 million of our fellow citizens to the curb.) ...
But the ugliest thing to witness on a very ugly day in the United States Senate was what John McCain did to what was left of his legacy as a national figure. He flew all the way across the country, leaving his high-end government healthcare behind in Arizona, in order to cast the deciding vote to allow debate on whatever ghastly critter emerges from what has been an utterly undemocratic process. He flew all the way across the country in order to facilitate the process of denying to millions of Americans the kind of medical treatment that is keeping him alive, and to do so at the behest of a president* who mocked McCain's undeniable military heroism.
... the Straight Talk Express is in the ditch. The Affordable Care Act was the product of endless hearings and at least 100 amendments proposed by Republicans. It was scored by the CBO. The Senate debated it for almost a month, and the senators knew what was in it. Right now, the bill that John McCain facilitated likely will be one that isn't scored by the CBO, and the Freedom Caucus crackpots in the House are trying to defund the CBO and hand the job of scoring legislation to the Heritage Foundation. I would bet a substantial number of buffalo nickels that John McCain votes for whatever bill finally comes before him, no matter how many people's lives that bill makes miserable.