McCain had a lifelong conservative vote rate of 81% at the conservative Club for Growth. True GOP moderates like Maine Sen. Susan Collins and Alaska Sen. Lisa Murkowski have CFG scores of 35% and 55%, respectively. The Heritage Foundation gives McCain a lifetime rating of 60%, compared to 24% for Collins and 34% for Murkowski
What McCain was was a senator who wanted to work with Democrats done. Whether it was with Wisconsin Sen. Russ Feingold on campaign financial reform or Massachusetts Senator Ted Kennedy on immigration, McCain demonstrated a willingness throughout his political career to compromise in pursuit of broader goals.
The reason is simple: just about the rise of the tea party movement in The 2009-2010 word "compromise" became a dirty word in Republican politics. The compromise with many republicans has begun to be regarded only as a synonym for capitulation. The prevailing opinion among this new generation of conservatives was that George W. Bush – and the Republican leaders in both parties – had forgiven too much in the name of compromise with Democrats. Compromises always favored Democrats, they believed. The new view was that the Conservatives must follow the principle – and, more importantly, penalize those fake Conservatives who promised to stay in line at reelection and then "go to Washington" as soon as they reach their limits In 2010 alone, three GOP senators – Murkowski, Dick Lugar of Indiana and Bob Bennett of Utah – lost their candidacy for reelection. (Murkowski led an election campaign in parliamentary elections and won.) McCain was in the same year in the election campaign and faced with an ideological challenge of former MP J. D. Hayworth. The campaign that McCain led reflected the drastic changes in his party. The incumbent group threw more than $ 20 million into the main competition race and was known to run a campaign against immigration that required him to complete the "Dangered Fence."
McCain won the race convincingly but at a cost. Even he was forced to bend in the midst of the swirling winds that overtook the party. (This was not the first time that McCain had chosen political preference over the principle, but having lost nearly the Republican President's nomination in 2007 for support of comprehensive immigration reform, he moved away from it – a key decision for his later march to the nod of 2008.)
When McCain reelected for election in 2016, the Donald Trump phenomenon seized the party. Politicians who formed conservative compromise leaders – Marco Rubio, Jeb Bush and John Kasich, to name only three – were abandoned by Trump, who, despite his democratic past and all-embracing political declarations, channeled the unreflective conservatism that many Republicans into Congress had run and won in the last ten years.
A single moment symbolizes the state of the party at this moment. In July 2015, just days after the formal announcement of his candidacy, Trump McCain said at an election event in Iowa, "He's not a war hero, he was a war hero because he was captured, I like people who were not caught."  The presumption within the political class was that Trump had ended his campaign with this one comment before it even started. "Donald Trump could have finally crossed the line," read at the moment the issue of Politico's news. No matter what you think of McCain's policy, it's impossible to question his service to the countryside – especially the more than five years he spent in a North Vietnamese prison camp.
Only that Trump's comment did not end his campaign has reinforced it. The republican activist base hated McCain because he had the audacity to work with Kennedy over immigration because he was unwilling to stand for any conservative politics, no matter what personal views he had. This kind of perceived apostasy was exactly what Trump was running to liberate the Party – and the GOP base was cheering instead of mocking his comments on McCain.
The simple fact is: The current political world we live in is not The one McCain – or those he served in congress during his first two decades – would even recognize. If John McCain were to run for the Senate in Arizona for the first time in this environment, he would almost certainly lose to an ideologically more consistent Republican who promised Trump unshakable support. Prejudices in the age of the Tea Party and Trump are something that every Republican "establishment" politician is now afraid of, because even the slightest trace of criticism of Trump could put you on the wrong side of the ledger if all votes are counted. Forget about working with Democrats in the corridor. This is a political death wish.
The simple fact is that our politics are simply not prepared to produce or promote another John McCain. Pro-Trump conservatives will consider that a good thing. With the RINOs and all that out. But I would ask you to scroll back to the beginning of this post to look at McCain's electoral rating of the two most notable conservative out-groups in the country. John McCain was not temperate. He was open to compromise. This distinction was almost completely destroyed in the pursuit of unconditional political fidelity.