The South Carolina Republican announced he would be ending his campaign in an exclusive interview with CNN's Kate Bolduan on Monday, saying he never managed to get momentum in the race. Graham failed to register even 1% in some polls.
Donald Trump, who Graham frequently charged was a disaster for the GOP, returned the feeling on Monday at a rally in Michigan.
"I'm extremely sad. He was nasty to me. Wasn't he nasty? Ew," Trump said. "I won't say how many left, but a lot of people are starting to leave, they're gonna start to leave. But everybody that's going -- Wouldn't it be nice? That should happen with our country -- everybody goes against us, down the tubes."
But most of his peers in the Republican race wished Graham the best -- now down to 12 main candidates -- especially fellow moderate Republicans.
Asked about Graham's departure while campaigning in New Hampshire, Florida Sen. Marco Rubio praised his strong advocacy of military strength.
"I thought he was one of the most forceful voices on any of the debate stages about rebuilding our military," Rubio said.
He called Graham a "good guy, very funny guy. We'll miss his humor on the campaign trail but we'll look forward to it on the Senate floor."
At a separate campaign event in New Hampshire, New Jersey Gov. Chris Christie echoed Rubio.
"I have great respect and admiration for Sen. Graham," Christie said. "We agree on many many issues and he was a real benefit to have in this race. I'm sorry he has dropped out, that's a personal decision."
Former Florida Gov. Jeb Bush was one of the first to wish Graham well.
"Nobody is more clear-eyed about ISIS than my friend @GrahamBlog. As he leaves the race I hope our party & country listen to his counsel," Bush tweeted
"Enjoyed Sen. @LindseyGrahamSC's wit & respect his seriousness on nat'l security -- experience matters. Best wishes to him. -John," Ohio Gov. John Kasich tweeted
Graham had in recent weeks been Trump's antagonizer in chief, criticizing the mogul and Texas Sen. Ted Cruz for being too right-wing for the party.
"Thank you to my friend @GrahamBlog for adding his strong national security voice to this race. It was much needed during this time of crisis," tweeted
Rick Santorum, who has like Graham been relegated to the lower tier debates in the race.
Former Virginia Gov. Jim Gilmore noted Graham's departure gives his pitch a boost.
"Sen. Graham recognizes the threat to America. As the only remaining veteran in the race I will carry the banner for veterans in this race," Gilmore tweeted
Gilmore also retweeted a follower saying he hoped Gilmore would be included in more presidential debates with Graham ending his campaign. Gilmore has failed to qualify for the debates based on minimum polling requirements.
Retired neurosurgeon Ben Carson kept his regards simple.
"Wishing @LindseyGrahamSC the best going forward," he tweeted
Former presidential candidate Mitt Romney also lamented losing Graham's "unique voice," but said the race will go on.
"While the race will miss his unique voice of truth and experience, the @LindseyGrahamSC fight must carry on," Romney tweeted
Democratic front-runner Hillary Clinton's spokesman wrote that losing Graham means losing the most moderate position on immigration in the GOP field.
"With Graham out, there's no one left in GOP field who clearly supports comprehensive immigration reform plan that has a path to citizenship," Brian Fallon tweeted
His fellow moderate Republican and friend, Arizona Sen. John McCain, also lamented Graham's departure from the contest on Monday.
"With Sen. Lindsey Graham's announcement, Republicans lost our most qualified, thoughtful, fearless and honest presidential candidate, not to mention the candidate with the best (and it seemed sometimes the only) sense of humor," McCain said in a statement. "As sorry as I am to see Lindsey's candidacy end, I understand his reasons, and I'm as proud of him as I've ever been for his exemplary service to our party and our country."