Mr. Graham’s personal story is well known: He grew up in the back of a bar owned by his parents, who died when he was in his 20s, leaving him to care for his 13-year-old sister. In the Senate, where he has served since 2002, he teamed up with Mr. McCain, partly because of their shared interest in military affairs (Mr. Graham is a retired colonel in the Air Force reserve) and they traveled the world together. He wept on the Senate floor when the older man died.
“It’s the closest thing he ever had to a father,” Mr. Gowdy said.
He has long been known as a kind of happy-go-lucky independent thinker. He voted to confirm two of President Barack Obama’s Supreme Court nominees, Sonia Sotomayor and Elana Kagan, which was one reason he was so angry at the Democrats’ opposition to Justice Kavanaugh. He also likes being in the middle of things. Whenever there is a Senate “gang” — a self-appointed caucus of problem-solvers — Mr. Graham seems to be in it.
“I like being relevant,” he said.
He has also done an especially artful job of befriending the president, often through flattery — “I try to start most conversations with a compliment” — which has won him Mr. Trump’s ear and the rarefied status of presidential golf partner. He views himself as uniquely positioned to guide a president inexperienced on matters of policy.
“I enjoy his company,” Mr. Graham said. “I’ve spent more time talking to him than any president — all of them combined.”
In the opening weeks of the Trump presidency, Mr. Graham promised to use his Senate Judiciary subcommittee on crime and terrorism to launch a bipartisan, no-holds-barred investigation of Russian interference in the 2016 election. At the same time, he reached out to Jared Kushner, the president’s son-in-law, as a potential partner on immigration and an overhaul of criminal justice laws.
Mr. Trump then invited Mr. Graham for lunch and sought the senator’s counsel on North Korea and Iran. The Russian investigation wrapped up quietly.
But the détente was complicated; Mr. McCain hated Mr. Trump. Mr. Graham, with the help of Mr. Kushner, tried to engineer a rapprochement, persuading the president to host Mr. McCain and his wife, Cindy, at the White House for dinner.