"Ronnie and I always waited until everything was decided, and then we endorsed," the Republican matriarch said in March. "Well, obviously this is the nominee of the party." They were the only words she would speak during the five-minute photo op.
In a written statement, she described McCain as "a good friend for over 30 years." But that friendship was strained in the late 1970s by McCain's decision to divorce his first wife, Carol, who was particularly close to the Reagans, and within weeks marry Cindy Hensley, the young heiress to a lucrative Arizona beer distributorship.
The Reagans rushed to help Carol, finding her a new home in Southern California with the family of Reagan aide Edwin Meese III and a series of political and White House jobs to ease her through that difficult time.
McCain, who is about to become the GOP nominee, has made several statements about how he divorced Carol and married Hensley that conflict with the public record.
In his 2002 memoir, "Worth the Fighting For," McCain wrote that he had separated from Carol before he began dating Hensley.
"I spent as much time with Cindy in Washington and Arizona as our jobs would allow," McCain wrote. "I was separated from Carol, but our divorce would not become final until February of 1980."
An examination of court documents tells a different story. McCain did not sue his wife for divorce until Feb. 19, 1980, and he wrote in his court petition that he and his wife had "cohabited" until Jan. 7 of that year or for the first nine months of his relationship with Hensley.
Although McCain suggested in his autobiography that months passed between his divorce and remarriage, the divorce was granted April 2, 1980, and he wed Hensley in a private ceremony five weeks later. McCain obtained an Arizona marriage license on March 6, 1980, while still legally married to his first wife.
Until McCain filed for divorce, the Reagans and their inner circle assumed he was happily married, and they were stunned to learn otherwise, according to several close aides.
"Everybody was upset with him," recalled Nancy Reynolds, a top aide to the former president who introduced him to McCain.
By contrast, some of McCain's friends, including the Senate aide who was at the reception where McCain first met Hensley, believed he was separated at that time.
Albert "Pete" Lakeland, the aide who was with McCain at the reception in Hawaii in April 1979, said of the introduction to Hensley: "It was like he was struck by Cupid's arrow. He was just enormously smitten."
As the pair began dating, Lakeland allowed them to spend a weekend together at his summer home in Maryland, he said.
The senator has acknowledged that he behaved badly, and that his swift divorce and remarriage brought a cold shoulder from the Reagans that lasted years.
In a recent interview, McCain said he did not want to revisit the breakup of his marriage. "I have a very good relationship with my first wife," he said. In his autobiography, he wrote: "My marriage's collapse was attributable to my own selfishness and immaturity. The blame was entirely mine."
Tucker Bounds, a McCain campaign spokesman, said: "Of course we will not comment on the breakup of the senator's first marriage, other than to note that the senator has always taken responsibility for it."
Carol McCain did not respond to a request for an interview.
About all she has ever said is this to McCain biographer Robert Timberg: "John was turning 40 and wanting to be 25 again."