Even McCain's former adviser in 2000, GOP strategist Mike Murphy, told MSNBC that Democratic presidential nominee Joe Biden's win in the Copper State could be McCain's "revenge" against President Trump, with whom he had a contentious relationship.
"If @JoeBiden wins, it will be fitting that @realDonaldTrump was undone by a petty grievance with an American war hero and public servant of the highest character: Sen. John McCain," wrote former Trump White House Communications Director Anthony Scaramucci.
"It would be poetic justice if Trump’s pettiness toward Sen. McCain (AZ) cost him the election," "Anonymous" author and former Trump official Miles Taylor tweeted. "His demand that we *not* lower U.S. flags in honor of the late war hero is what prompted me to write the anonymous op-ed in the first place."
Politico magazine's editor-in-chief Blake Hounshell wrote that Arizona's shift towards Democrats was "like the ghost of John McCain turning down his thumb one last time," a reference to the senator's famous vote against a repeal of Obamacare, and CNN's Ana Navarro-Cárdenas tweeted that she imagined it as "John McCain getting the last laugh."
McCain's feud with Trump was longstanding, spanning nearly two decades.
In January of 2000, as Trump was making an early run for president, he criticized McCain's service during the Vietnam war.
A Naval aviator, McCain was taken prisoner by the North Vietnamese after his plane was shot down on a bombing mission in 1967. He refused an early release, offered because his father was an admiral, and didn't return home until 1973.
“Does being captured make you a hero?" Trump said in an interview on CBS. "I don’t know. I’m not sure.”
Yet, despite previous comments, the president also changed course on McCain several times throughout 2016.
McCain defended Trump following comments the president made on soldiers with post-traumatic stress disorder but withdrew any support for Trump just days later following the release of a 2005 recording in which Trump discussed kissing women and grabbing them by their genitalia.
In July of 2017, McCain's cancer diagnosis became public, though he fought the disease for another year.
After McCain's death, U.S. flags at federal buildings were raised just two days after they had been lowered, a move that was widely criticized.
Now, McCain's wife, Cindy, is supporting Biden and was appointed to the advisory board for his transition team ahead of the election.
Biden is the first Democrat to clinch the state since President Bill Clinton won in 1996. Before that, a Democratic candidate had not won since Harry Truman's re-election in 1948.