Seven months after the former POW died at the age of 81 from cancer, and after the president spent the weekend making accusations about him on Twitter, Mr Trump was asked why he was attacking a dead man.
The president claimed he was angry when the then Arizona senator had in 2017 dramatically voted against a White House-backed plan to repeal and replace Obamacare, when Mr McCain had campaigned to get rid of the programme.
Mr Trump claimed the late senator’s actions in reversing his position at the last minute and displaying a “thumbs down” on the floor of the senate, had been “disgraceful.”
“And there are other things,” Mr Trump added. “I was never a fan of John McCain and I never will be.”
Mr Trump, who secured five deferments to avoid the Vietnam draft, has long had a testy relationship with McCain, who spent more than five years as a POW after his jet was shot down. At least two of the years he spent as a prisoner, were in solitary confinement.
While campaigning in 2015 for the Republican nomination, a position McCain had secured in 2008 when he ran and lost against Barack Obama, Mr Trump disputed the suggestion that his fellow Republican was a war hero.
No one will ever love you the way they loved my father.... I wish I had been given more Saturday’s with him. Maybe spend yours with your family instead of on twitter obsessing over mine? https://t.co/q7ezwmHiQ4— Meghan McCain (@MeghanMcCain)March 16, 2019
“He’s not a war hero,” said Trump. “He was a war hero because he was captured. I like people who weren’t captured.”
Mr McCain never hid his dislike of Mr Trump, though he was obliged to outwardly support him to some degree because he relied on many of the president’s supporters to vote for him in his 2016 senate reelection campaign.
This weekend, Mr Trump, who was asked by McCain’s family not to attend his state funeral in Washington DC, continued his attacks on the dead man.
“Spreading the fake and totally discredited Dossier is unfortunately a very dark stain against John McCain,” he tweeted, Ken Starr, the independent counsel who investigated Bill Clinton and who had made the comments in a Fox News interview.
He also tweeted of McCain: ”He had far worse ‘stains’ than this, including thumbs down on repeal and replace after years of campaigning to repeal and replace!”
McCain’s family has hit back at the comments, which included a false accusation that the senator had come “last in his class” at the United States Naval Academy at Annapolis. The late senator’s daughter, Meghan McCain, told ABC News that Mr Trump “spends his weekend obsessing over great men because he will never be a great man.”
“My father was his kryptonite,” McCain said.
“That tells you everything you need to know about his pathetic life right now. I genuinely feel bad for his family. I can’t imagine having a father that does this on the weekends.”