(CNN) - Senator Lindsey Graham is ending his presidential campaign, he told CNN during an exclusive interview airing Monday.
"I'm going to suspend my campaign. I'm not going to suspend my desire to help the country," the South Carolina senator said in a wide-ranging and candid discussion in which he acknowledged: "I've hit a wall here."
He is planning to make the official announcement in an email to supporters Monday morning.
Graham is known for his quick wit and famous for his one-liners (just ask Princess Buttercup about his retort from the last debate), but he was sober, serious and emotional as he described his decision to leave the race just weeks before the voting begins.
One thing is clear: Graham still wants his voice heard on the direction his party is headed, especially with regard to the Middle East.
"Here's what I predict. I think the nominee of our party is going to adopt my plan when it comes time to articulate how to destroy ISIL," he said. "We've fallen short here, but the fight continues. To those who are doing the fighting, I want to be your voice. To those in the Republican Party who want to win, check my plan out. Hillary, if you get to be President, I'll help you where I can. I hope you're not. But if you are, I'll be there to help you win a war we can't afford to lose."
Graham's decision comes just days after the CNN Republican Presidential Debate in Las Vegas, where he was widely viewed as dominating the undercard debate.
However, Graham was never able to break onto the main stage after announcing his candidacy in early June — a reality of the Republican Party's new debate structure that he blames at least in part for his struggles. Graham limped along at less than one percent in national polls, and, in the most recent CNN/ORC national poll, he barely registered. He failed to even qualify for the undercard round in the Fox Business debate in November.