His last major endeavor with Democrats and Republicans was legislation to further punish Russia for its invasion of Ukraine, legislation he sponsored along with Senator Richard Blumenthal, Democrat of Connecticut. A bipartisan group of senators announced before the service that they had reached a deal on that sanctions bill and advanced it on an 86 to 12 procedural vote Tuesday night in Mr. Graham’s honor.

Many Democrats attended the services on Capitol Hill and at the cathedral, a testament to their lasting personal affection for Mr. Graham and a nod to the rituals of the capital. Not on hand, however, was former President Joseph R. Biden Jr., who was once close to Mr. Graham but grew estranged when the senator joined Mr. Trump’s attacks on his son Hunter Biden.

It said something too about the pecking order of Mr. Trump’s Washington that his son Eric Trump and daughter-in-law Lara Trump were given seats in the front row along with the president and vice president, while the secretaries of state and defense, Marco Rubio and Pete Hegseth, were relegated to the second row.

Also on hand was Justice Brett M. Kavanaugh, whose confirmation to the Supreme Court was secured in part by Mr. Graham who became his most passionate defender during Senate hearings in 2018 when the nominee was accused of sexually assaulting a fellow student during high school.

Mr. Trump used the occasion to share stories, including the time he and Mr. Graham ran against each other in 2016 for the Republican presidential nomination. At one point, in an act of revenge for some harsh things Mr. Graham had said, Mr. Trump gave the senator’s personal mobile phone number out publicly.

“His phone totally — I don’t know what he did with it, but it exploded,” Mr. Trump recalled. “That was the beginning of a friendship, in a way. But it was Lindsey who had the last laugh because, while I blew up his phone, oh, for one day, we became great friends, and Lindsey did not stop calling me for the next 10 years.”

Robert Jimison and Chris Cameron contributed reporting.