WASHINGTON — John McCain’s close friend Lindsey Graham mixed laughter and tears on the Senate floor Tuesday as he remembered “Operation Maverick,” which he described as lessons in choosing “what’s right at your own expense.”

“He taught me that honor and imperfection are always in competition,” Sen. Graham said, reading from a handwritten outline next to McCain’s empty desk, now topped with roses. “I do not cry for a perfect man. I cry for a man who had honor and always was willing to admit to his imperfection.”

The South Carolina Republican added, “There’s a little McCain in all of us.”

Graham’s tears were the rawest point in a day in which members were still coming to grips with a Senate now permanently without McCain’s wily, white-haired presence, something that had been a constant feature of the institution for more than 30 years.

At one point, Sen. Joe Manchin of West Virginia stepped behind the desk, crossed himself, kissed his fingers and touched the black draping. At another, Republican Sens. Susan Collins of Maine, Tim Scott of South Carolina and Manchin formed a tight circle around McCain’s spot and admired the roses.

McCain died Saturday at home in Arizona after 13 months battling brain cancer. He had not been back to Washington since December because of his illness, but stayed engaged in policy debates and expressed his disdain for President Donald Trump in their ongoing feud.

But now he was truly gone, his absence confirmed by his empty chair and desk along a much-traversed aisle.

“When you walk by Sen. McCain’s desk and you see the black drape and the bowl of white roses, it really underscores the loss,” said Sen. Bill Nelson, D-Fla.

As the Senate churned though business Tuesday, McCain’s death sat very much at the center of proceedings and at the front of his colleagues’ minds. Only four of them know a Senate without McCain, who was elected in 1986 and had become a mentor and moral compass to newcomers. Several defended him against attacks from Trump, who questioned McCain’s heroism as a prisoner of war and chafed over McCain’s thumbs-down vote that sank the repeal of national health care.

“No one is more worthy of the word ‘hero’ than John McCain,” Utah Sen. Orrin Hatch, the most senior Republican in the Senate, said in his own speech.

Graham’s eyes and nose were red when he entered the chamber, and he unfurled his sorrow with emotion rarely seen on the televised Senate floor.

“I have been thinking about this. I have been dreading this. And now I’m going to do this” eulogy, Graham said, identifying himself as McCain’s “political wingman, code name Little Jerk.”