Joe Biden’s emotional tribute Thursday doubled as a lecture to today’s politicians, particularly the couple dozen U.S. senators who were on hand.

“All politics is personal,” the former vice president said at the memorial service here for John McCain. “It’s all about trust. And I trusted John with my life.”

Biden, who bonded with the 2008 Republican presidential nominee in their 22 years together in the Senate, explained that their bipartisan friendship now seems as if it came from “another age.” At one point, Biden turned to his left inside North Phoenix Baptist Church, stared at the current senators and essentially chastised them about how they have let a great institution wither into today’s daggers-drawn partisan environment.

“We both lamented watching it change,” Biden said, recalling the time in the mid-1990s when other senators questioned why the Delaware Democrat and Arizona Republican sat together so often on the Senate floor. “That’s when things began to change for the worse in America, in the Senate.”

Biden used the 30-minute speech to paint a vision of the Senate and American politics that once was, and might someday be again, if leaders would fight for that cause.

As he considers a third bid for president in 2020, Biden, 75, might find that message out of touch with this era’s politics. Each side has drifted away from trying to persuade voters in the middle and instead tries to drive up turnout from their most loyal base supporters.

The result has been the decline of senators willing to compromise and the rise of rank partisans, leaving little room for negotiation and less inclination to even socialize together.

So many hold grand political ambition, as president or vice president, that they fear getting labeled with the B-word (bipartisan), because they might not be trusted by the ideologues who dominate early voting in presidential primaries.

There are still some true pairings that make things work, particularly Sens. Lamar Alexander (R-Tenn.) and Patty Murray (D-Wash.), leaders of the Health Committee, who were on hand here Thursday. They have delivered several big pieces of legislation in recent years, including a rewrite of K-12 education laws. But their most recent heavy lift — a bid to stabilize the private health-care markets — was brushed aside by conservatives.

The McCain-Biden bond is truly unique.

They met when McCain was stationed in the Senate in the late 1970s as the Navy’s liaison, leading to many trips abroad with senators.

Biden, who had just turned 30 when he was sworn in in 1973, looked to McCain as a contemporary. They hit it off right away. Not just because they were close in age but also because each man had been through hell on earth — Biden’s first wife and daughter dying in a car crash in 1972; McCain enduring 5½ years of captivity as a prisoner of war in Vietnam.

Those trips around the world forged a bond that lasted through many policy fights, particularly over the Iraq War, and survived the 2008 presidential campaign.

“We would sit on that plane, and late into the night, when everyone else was asleep, and just talk,” Biden recalled Thursday. The topics ranged from family to politics to global affairs, but not their greatest hardships.

“We talked about everything except captivity and the loss of my family,” he said.

They instinctively knew, without going into details, each had suffered an unspeakable tragedy.

In August 2009, McCain and Biden delivered tributes at a memorial service for Edward M. Kennedy in Boston. Their mutual friend, the Democratic senator from Massachusetts for 47 years, had died after a 15-month battle with glioblastoma, a deadly form of brain cancer.

“Ted and I shared the sentiment that a fight not joined was a fight not enjoyed,” McCain said that night at the John F. Kennedy Presidential Library.

Biden, Kennedy and McCain all came from another tradition that’s disappeared: taking a risk. McCain linked arms with Kennedy and tried on multiple occasions to pass sweeping immigration legislation even as he knew the issue was becoming toxic to conservative voters ahead of the 2008 primaries.

Biden still tries to tell liberals that they cannot hate supporters of President Trump but should understand them and their pain — at a time when most other 2020 contenders think they can grow the Democratic base to win back the White House.

In 2015 Biden’s oldest son, Beau, the former Delaware attorney general with his own bright political future, died of the same form of brain cancer as Kennedy.

Last October, in front of Philadelphia’s Independence Hall, Biden presented McCain with the Liberty Medal, an honor from the Constitution Center. McCain wiped tears from his eyes as Biden recounted how his son found “courage” in his cancer diagnosis from knowing what McCain suffered in Vietnam.

On Saturday, nine years to the day of Kennedy’s passing, glioblastoma took McCain’s life.

Biden looked straight at the McCain family Thursday and told them they were entering a period of pain “so sharp and so hollowing.” They would overcome it and would eventually forget the painful past 13 months, he promised, the same way he now envisions Beau full of health on the lake near the Biden family home.

The former vice president said McCain’s death has so deeply affected Americans because of what seemed like the passing of a generation of politicians who still believed in national greatness, shared ideals that went beyond party labels and a belief that better days are ahead.

He mocked the award that the two men received in 2016 for their civility and bipartisan approach in politics.

“That’s how it’s always supposed to be,” Biden said, turning to Sen. Jeff Flake (R-Ariz.) to express the outrage at how bad things have gotten. “Getting an award for civility.”

Flake, a McCain disciple, is considered one of the most civil senators and has clashed with Trump. It made him so unpopular among Arizona conservatives that he is retiring at the end of the year.

Rep. Martha McSally (R-Ariz.) won the nomination to succeed Flake on Tuesday, largely by distancing herself from McCain and embracing Trump.

As he closed, Biden again drew to a whisper as he lamented what McCain’s loss meant.

“We shall not see his like again,” Biden said.