McCain was elected to the Senate from Arizona six times but twice thwarted in seeking the presidency.
John McCain was born August 29, 1936, in the Panama Canal Zone when the area was still under USA control.
McCain had not been on the Senate floor in months, remaining at his Arizona home for treatment of glioblastoma - the same form of brain cancer that took the life of another Senate giant, Democrat Ted Kennedy, in 2009. During his final years in the Senate, McCain was perhaps the loudest advocate for USA military involvement in Iraq, Syria, Libya and more.
McCain was the son and grandson of admirals and followed them to the U.S. Naval Academy.
ASU football head coach Herm Edwards spoke about McCain after the team's practice Saturday.
"Before I leave, " he wrote, "I'd like to see our politics begin to return to the purposes and practices that distinguish our history from the history of other nations". The victor of that election would serve the remainder of McCain's term through 2022. He loved me, and I loved him. An icon. An American hero. "He is a guy that brings people together and that's a sad loss for our country".
That moment appeared to cement McCain's reputation as a politician with a fierce independent streak, although his overall voting record shows he was more partisan than his public image. I am blessed and humbled by our friendship.
In his valedictory memoir, "The Restless Wave", McCain wrote of the world he inhabited: "I hate to leave it".
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He also advocated support of the country's Native American population and condemned torture and "enhanced interrogation" techniques such as waterboarding used in the War on Terror. In this Lifetime movie parody, Amy Poehler stars as a woman whose husband, played by McCain, continually invades her personal space - whether she's in the shower, coming in the front door, or even on the witness stand testifying against him.
That debate continues after Senator McCain's passing, with one of the most powerful and passionate voices for American global leadership silenced, amid great uncertainty as to who in the US Congress will advance his legacy and the case of American internationalism. Fact is. he had surpassed expectations for survival.
During the 2008 election, McCain put in two appearances on Saturday Night Live, including one opposite Tina Fey, who played VP candidate Sarah Palin (watch it below). Arizona is one of 36 states where Senate vacancies are handled this way, according to the National Conference of State Legislatures.
Domestic politics is often said to stop at the water's edge: that is, while overseas, politicians don't criticise the governments or leaders of their home countries.
"His courageous fight as a prisoner of war, as a principled senator and during his illness speak to his outstanding character", Rep. Mia Love, R-Utah, said in a statement Saturday.
Following the announcement of 81-year-old John McCain's death, the public took to social media to express their condolences and share mixed feelings about the Republican's life and deeds.
McCain's condition worsened last fall, and he has been in Arizona since December. Before his death, McCain's wife Cindy said in a tweet that the McCain family was "overwhelmed by the outpouring of love and support from around the world".