Right now, he's a hero in a lot of places for piggybacking on the work of his fellow Republicans Susan Collins of Maine and Lisa Murkowski of Alaska and not jeopardizing health care for more than 400,000 Arizonans.
But don't forget he once held the title of least popular senator in the country.
Let's take a look back at McCain's long career of politics, war-hero patriotism, and that pesky presidential failure.
At 80 years old, McCain has become somewhat of a grandfather figure to the American people, which is probably what gave him the authority to scold the Senate over its childish handling over the health care bill. And like every senile grandpa, he completely disregarded his own rant and voted in favor proceeding with bill instead of killing it.
The "maverick" entered politics in 1982, when he won a seat in the House of Representatives. He adopted Arizona's conservatism and was re-elected into the House of Representatives before moving to the Senate. His presidential prospects took a hit when he was linked to the "Keating Five," which landed him in the middle of a federal investigation of one of the biggest savings-and-loans scandals of the late 1980s.
However, he came out unscathed and with no charges.
Fast forward a couple decades and several Senate runs, McCain finally stepped fully back into the national spotlight during the 2008 presidential election. He almost made big news when he considered Democrat Joe Lieberman as his running mate. Then he made even bigger news, but surrendered the spotlight when he chose Alaska governor and walking parody Sarah Palin.
When it came to his opponent, Chicago native and Democrat Barack Obama, McCain was classy enough to keep race out of the equation and focus on the issues. Several times during a town hall meeting, he stopped participants who were starting to make a racist comment and defended Obama as a "family man."
However, that didn't stop his campaign from darkening Obama's skin in campaign ads. In the end, it didn't matter, as Obama prevailed and won the presidency. Some maverick fans took McCain's crushing defeat in the Electoral College to Obama harder than others. A study found that male supporters of McCain had a 25 percent drop in testosterone after they heard the bad news.
Before the controversial Great Wall of Trump was the Danged McCain Fence. The TV ad aired in May 2010 to promote the Border Security Enforcement Act of 2011.
A few years later, McCain revisited Nogales to get a tour of the barricade, and Twitter magic was created. While tweeting about his visit, McCain told his followers that he watched a woman successfully climb and clear the danged fence. The woman was detained, but the moment of dramatic irony spread freely in the Twittersphere, garnering hundreds of responses and retweets.
Just witnessed a woman successfully climb an 18-ft bollard fence a few yards from us in #Nogales pic.twitter.com/GnMwEeQwDB
— John McCain (@SenJohnMcCain) March 27, 2013
McCain has been around long enough that, like most old men, he's said to hell with the rules. During a Senate session on a possible military strike in Syria, a Washington Post photographer snapped a photo of the Senator not paying attention and playing poker on his iPhone instead. And guess what? He didn't give a damn.
Scandal! Caught playing iPhone game at 3+ hour Senate hearing - worst of all I lost!
— John McCain (@SenJohnMcCain) September 3, 2013
McCain ran for his sixth term in the Senate in 2016 against Democrat Ann Kirkpatrick. Kirkpatrick relentlessly went after McCain's complicated relationship with Donald Trump as a way to take him down. At one point, The Washington Post said McCain was the eighth most likely incumbent to lose.
But what appeared to be a tight race in the spring soon widened as McCain's polling numbers went from favorable to victorious in the fall. For a full recap of all the issues he and Kirkpatrick butted heads on, click here.
The exchange of insults between Trump and McCain began even before the reality star entered the White House. McCain formally denounced Trump after the future president said he didn't consider McCain a war hero, saying, "I like people who weren't captured."
Most Americans shook their head in disgust, but some Arizona residents were finally justified in questioning McCain's war hero status. This select group of individuals, led by Mesa bus driver Craig Willbanks, were hellbent on proving that McCain was a traitor and made deals with communists while he was kept as a prisoner of war.
Before he decided the fate of millions of Americans' health care, McCain's own health made headlines. He announced that he had been diagnosed with gliobastoma, an aggressive form of brain cancer. Immediately, the internet reacted, some with warm wishes, some with conspiracy theories, and others with a little herbal help. And many thought the cancer might have led to his bizarre questioning of former FBI Director James Comey.
One response, though, set Twitter on fire. Los Angeles Times reporter Jessica Roy accused McCain of turning his back on an Arizona native who died of the same cancer. It just so happens the Phoenix New Times wrote about that Arizona native. Before an all-out Twitter civil war broke loose, Roy tweeted an apology because she made the claim without evidence.
Now that he's ruffled a few feathers in Washington, McCain has announced he will be returning to the Mayo Clinic in Phoenix to undergo radiation and chemotherapy. He's promised to maintain his work schedule, though, so this popularity may not last long.I regret what I wrote and sincerely apologize. (2/2)
— Jessica Roy (@jessica_roy) July 20, 2017