In an interview with CNN's Kate Balduan, the South Carolina senator acknowledged that his campaign had "hit a wall." He also released a campaign video on YouTube officially announcing the suspension of his run.
Graham told Balduan that he was satisfied with how his unsuccessful campaign played out.
“The one thing I feel really good about is I did it with a smile on my face," he told Balduan. "I talked about things that are important to me, and somebody better fix one day."
Graham, who was one of the most hawkish candidates in the crowded Republican field, took credit for pushing the race toward the issues he was devoted to: securing America's borders and fighting terrorism abroad.
“I got into this race to put forward a plan to win a war that we cannot afford to lose and to turn back the tide of isolationism that was rising in our party," he said in his announcement video. "I believe we made enormous progress in this effort.”
The South Carolina senator said that he planned to remain active in shaping Republican Party politics.
"I will suspend my campaign. I'm not going to suspend my desire to help the country," he said on CNN.
Graham has consistently polled near the bottom of the Republican field. He told CNN that his decision to drop out was not fueled by the December 21 deadline to keep his name off the ballot in his home state of South Carolina. A Real Clear Politics average of Graham's poll returns in that key early primary state was 1.7 percent.
Wisconsin Gov. Scott Walker (R), Louisiana Gov. Bobby Jindal (R) and former Texas Gov. Rick Perry (R) have also dropped out of the race.
Watch Graham's announcement video below.