Republican presidential candidate Lindsey Graham ended his campaign for the White House on Monday, telling CNN that he "hit a wall" in his bid for the nomination.

The South Carolina senator has struggled in the polls since he joined the race, and the announcement came the same day as a deadline for him to decide whether he wanted to stay on his home state's ballot.

Graham entered the crowded race with hopes of forcing a broader debate on foreign policy, but his low polling numbers relegated him to the second-tier of the debates and he was overshadowed by Donald Trump and other outsiders.

Most polls showed him around 1 percent, including those in New Hampshire, where he has concentrated most of his efforts. His troubles extended to his home state: A Winthrop University poll of South Carolinians put him at 2 percent.

The move frees the South Carolina politicians and operatives who joined Graham's campaign - or stayed neutral out of respect to the native son - to pick new sides before the state's February primary. Graham's former rivals are now in a race to snap up the activists and consultants who aligned with Graham.

Graham, for his part, said he left the contest confident he made a lasting imprint.

"At the very first debate I said if any candidate did not understand that we need more American troops on the ground in Iraq and Syria to defeat ISIS was not ready to be commander in chief," he said in a YouTube message, referring to the Islamic State.

"At that time, no one stepped forward to join me. Today, most of my fellow candidates have come to recognize this is what's needed to secure our home."

Graham's candidacy was always a long shot. Here's a snippet from a piece our AJC colleagues Aaron Gould Sheinin and Daniel Malloy wrote in May ahead of his formal announcement that he was entering the race:

Two easy examples: He once said he'd be willing to raise taxes to save Social Security and he supports changes in immigration law that would allow some immigrants living in the country illegally to stay.

"He provides a really interesting standpoint on a lot of issues that most normal voters can agree with," said Taylor Mason, the third vice chairman of the South Carolina GOP. "He's really sensible, and the thing that a lot of people like about him in South Carolina is he doesn't care if you agree with him."

But in a state where the tea party still has great power, Graham risks being outflanked on the right in a presidential primary.