The Grand Old Party has had a full day to process the new reality that Donald Trump is officially its presumptive presidential nominee. And yet, none of the living members belonging to that elite group of Republican leaders who've shared the title appear eager to welcome the real estate mogul to the club.
Out of five former Republican presidential nominees alive today, only one - Arizona Sen. John McCain - has said he will support Trump, who effectively clinched the nomination on Tuesday after defeating his closest rival, Texas Sen. Ted Cruz, in the Indiana primary. Cruz dropped out of the presidential race that night, followed the next day by Ohio Gov. John Kasich.
All of the other living Republican presidential nominees have either not endorsed the current party standard-bearer, or said they would not be attending the Republican National Convention this summer, underscoring the deep division Trump's candidacy has created within the GOP.
Speaking to reporters Thursday in Phoenix, McCain said he would not be attending the convention. But he did vow to support Trump as the nominee.
"I will, as I said many times, I support the nominee of the party," the 2008 Republican presidential nominee said of the man who last year mocked him for being captured during the Vietnam War. McCain added: "I will do what I can to influence the campaign in the areas of national security that I think are most needed to be addressed."
Other former Republican nominees were not as accepting. An aide to Mitt Romney, who lost to President Barack Obama in 2012, said the former Massachusetts governor would not be attending the convention this summer, despite accepting the nomination there four years ago. Romney had encouraged Republicans to deliberately thwart Trump's path to the nomination earlier this year, even if it meant voting for a candidate who wasn't their favorite. Former Presidents George H.W. Bush and George W. Bush, meanwhile, also made clear this week that they had no plans either to attend the convention in Cleveland, or to endorse Trump.
Former Kansas Sen. Bob Dole, who won the Republican nomination in 1996, plans to briefly attend this year's convention, primarily for a luncheon hosted by his law firm, Alston & Bird, his office said Thursday. However, he has yet to issue a formal endorsement of Trump. "We'll have to wait and see how the convention plays out," his office said.
This article originally appeared on MSNBC.com.