The melee began, as they often do in politics, with simple umbrage. ‘‘This performance with our friend out in Phoenix is very hurtful to me,’’ Senator John McCain told Ryan Lizza of The New Yorker. He was referring to a massive rally that Donald Trump held a few days earlier in July to protest illegal immigration. McCain then followed with the kill shot. ‘‘What he did,’’ he said of Trump, ‘‘was he fired up the crazies.’’ In the annals of political deprecation, McCain’s charge of rallying the ‘‘crazies’’ was not terribly inspired. It was a far cry from, say, Teddy Roosevelt’s remark that William McKinley ‘‘has the backbone of a chocolate éclair’’ or Winston Churchill’s description of Clement Attlee, the British prime minister, as ‘‘a sheep in sheep’s clothing.’’ This was not even a Top 5 effort by McCain, who will sometimes refer to reporters as ‘‘Trotskyites’’ (often with affection) and last year dismissed protesters who interrupted a Senate hearing as ‘‘lowlife scum’’ (without affection). McCain is not so much a put-down artist as he is gifted at caricaturing entire sectors and viewpoints by way of dismissing them — in this case the border hawks who turned out for Trump.

But let’s pause on ‘‘crazies.’’ The word goes to the crux of how divisions are playing out in this peculiar campaign cycle among Republicans and, to some degree, among Democrats too. It is a slur that invites philosophical questions: Exactly who is crazy and who is not in today’s political environment? Are ‘‘crazies’’ an ascendant class in opposition to the same-old political traditions and tropes: Clintons, Bushes and McCains? Can ‘‘crazies’’ be worn as a badge of honor?

Of course, McCain never intended ‘‘crazies’’ as a compliment. ‘‘We have a very extreme element within our Republican Party,’’ he said in the same New Yorker interview. To McCain, ‘‘extreme’’ equals ‘‘crazy.’’ Their position falls well beyond the American mainstream in addition to emanating from unhinged minds. The word was a variant of the more colorful ‘‘wacko birds’’ that McCain deployed in 2013 to describe the Republican senators Ted Cruz and Rand Paul after they began a filibuster over the nomination of the incoming C.I.A. director, John Brennan. Taking vocal and often contrarian positions (or, if you prefer, grandstanding) can be a publicity magnet for any attention-hungry pol, no matter where he or she resides on the spectrum, political or otherwise. ‘‘It’s always the wacko birds on right and left that get the media megaphone,’’ McCain observed. This is true, although it’s also true of someone that tosses around quotable terms like ‘‘wacko birds.’’