WASHINGTON (Reuters) - When Washington’s political leaders gather in the U.S. Capitol on Friday to commemorate the late Senator John McCain, President Donald Trump will travel to one of his private golf clubs for a campaign fundraiser.

In a week of solemn events marking McCain’s passing, Trump has been and will be absent, a reflection of the animosity between the two men that lingered even after the Arizona senator’s death on Saturday from brain cancer.

Trump will also miss Saturday’s service at the Washington National Cathedral, where former President Barack Obama, the Democrat who defeated McCain in 2008, and Republican President George W. Bush will pay tribute to McCain.

Traditionally, sitting American presidents “serve as a source of solace and comfort” for the country at times of loss and tragedy, said Princeton University historian Julian Zelizer.

The Trump-McCain relationship left little room for that.

In 2015, not long after Trump kicked off his presidential campaign, McCain condemned his hard-line rhetoric on illegal immigration, accusing Trump of “firing up the crazies.”

Trump hit back, saying of McCain’s 5-1/2 years as a prisoner of war in Vietnam: “He was a war hero because he was captured. I like people who weren’t captured.” Trump received five deferments that got him out of military service.

Former Vice President Joe Biden wipes a tear while giving a tribute during memorial service for Senator John McCain at North Phoenix Baptist Church, Phoenix, Arizona, U.S., August 30, 2018. Matt York/Pool via REUTERS

More recently, McCain accused Trump of kowtowing to Russian President Vladimir Putin at a July summit in Helsinki. It was, McCain said, “one of the most disgraceful performances by an American president in memory.”

Trump in turn delayed issuing any statement after McCain’s death. At one point, the U.S. flag atop the White House that had been at half-staff was raised back up, then lowered again after Trump drew fire from Congress and veterans.

“The president’s actions in the first day of (McCain’s) death were so petty,” Zelizer said.

More broadly, Zelizer noted that many Republicans, including some in Arizona, had grown frustrated with McCain’s moderate stances on some issues, reflecting the changing nature of the Republican Party that Trump has seized upon.

Despite these tensions, most leaders from both parties in coming days will show they can rise above the political fray to recognize the passing of a respected colleague.

McCain was involved in planning the events around his funeral. He made it clear to family and friends that he wanted Democratic former Vice President Joe Biden, Bush and Obama to speak, but that Trump was not welcome.

Friday’s events in the Capitol will feature remarks by fellow Republicans Vice President Mike Pence, Senate Majority Leader Mitch McConnell and House of Representatives Speaker Paul Ryan, marking McCain’s 35-year career in Congress.

While he and McConnell had their differences, McConnell nonetheless has called McCain a “lion of the Senate.”

The public will file through the Rotunda for six hours to pay their respects to McCain by filing past his coffin, which will rest atop a pine board catafalque originally constructed in 1865 for President Abraham Lincoln’s casket.

The pallbearers at Saturday’s cathedral service will include Biden and liberal actor and activist Warren Beatty, alongside former Senator Phil Gramm and ex-Defense Secretary William Cohen, both Republicans.

Throughout U.S. history, only 32 times have people “lain in state” or “lain in honor” under the soaring Capitol Rotunda, including 11 presidents and unknown soldiers from World War I to Vietnam. The late Senator Daniel Inouye laid in state in 2012.