It's one of the newest punchlines in Washington: Lindsey Graham is running for president.

Last month, a Quinnipiac poll on Republican presidential contenders found the South Carolina senator near the bottom of the list, with a mere 1 percent of the vote. In January, when Graham was mulling a run, one fellow senator joked he wished he could see a list of Graham's supporters.

Freshman Republican senators such as Ted Cruz, Rand Paul, and Marco Rubio have for months used their Capitol Hill gigs to jockey for the job they want and have won attention from national media. By comparison, Graham—who announced his run Monday—is late to the game. But his colleagues say that doesn't matter. Graham's entry into the race gives foreign policy hawks more assurance that the GOP is not going to stray from its core philosophy come primary season.

"I don't think you should underestimate Senator Graham," Majority Whip John Cornyn said. "It is just that his focus has been on his state and on the issues he cares about. He has not been running for president or talking about running for president for a long time, so I think he is going to surprise a lot of people."

Graham is hardly an inexperienced politician. Colleagues say he's got an unparallelled depth of experience on foreign policy, especially compared to his competitors in the Senate, who have had less time in the upper chamber to build their foreign policy credentials. Some have had their big moments: In December, Rubio blasted the Obama administration's decision to restore diplomatic relations with Cuba. And in recent weeks, Paul has used the Patriot Act to bill himself as the candidate against government surveillance.

"Lindsey's got a lot of substance to him. He's not a one-trick pony," Senate Intelligence Chairman Richard Burr said. "I think Lindsey is going to influence what the national security debate is and what our foreign policy is, and I think that is important for the process."

Besides former Republican presidential nominee John McCain, there are few in the Republican Party who are as widely recognized for their hawkish foreign policy as Graham. He spent more than 30 years in the Air Force before retiring last month. He has been at the forefront in calling for more U.S. engagement in every corner of the globe, from Ukraine to Syria, and he has said the U.S. should put 10,000 troops on the ground to defeat the Islamic State. His campaign message Monday—that "the world is falling apart"—suggests Graham already has staked his claim as the foreign policy expert to beat. His entry may keep libertarian-minded Republicans like Paul from redefining the party's outlook on foreign policy, and pull the party to the right.

And because people don't expect Graham to win the Republican nomination, he may have more freedom to answer questions that might trip up his competitors. Take Jeb Bush, who has a better chance at the White House, but who spent a week attempting to explain whether he would have gone into Iraq in 2003.

Graham "has strongly held beliefs, and he doesn't bend at the first question at a press conference," said Matt Moore, the chairman of the South Carolina Republican Party. "That is a bit rare in this era of scripted campaign events and celebrity politics."

Of course, Graham isn't the only one calling for the United States to reassert itself in the world—Rubio and Texas Gov. Rick Perry have been doing so for years. But Graham is his own brand, perhaps one of the most respected hawks among his Senate colleagues. When the senator speaks up in party meetings, several of his colleagues reported, they listen.

"He should be taken very seriously because there is no one who knows and understands national security questions better than Lindsey," said former Sen. Joe Lieberman, who worked with Graham when he was in the Senate on everything from foreign policy to climate change.

On why Graham's competitors in the Senate are getting more attention: "I don't think there is a good reason for it, and the more this goes on ... the more he will be taken seriously," Lieberman said.

While Graham is a long shot for the nomination, he's shown before that when he enters a race, he's not interested in phoning it in. In 2013, he was blasted by conservative talk show hosts and criticized by tea partiers in his home state for working with Democrats on immigration reform. A year later, he easily won his deep red state's primary. The Club for Growth vowed to take him down, but not a single Republican congressman in the state vied to challenge the dean of the delegation. As Molly Ball so deftly put it in The Atlantic, "kicking the crap out of the tea party" was "the most fun Senator Lindsey Graham has ever had."

Graham didn't sit back and luck out back then. He worked for his win. He helped potential competitor Rep. Mick Mulvaney get a committee chairmanship in the House to make a Senate run appear less tempting. And, knowing competition could be coming his way, Graham went out and fundraised like crazy, racking up $12.7 million between his PAC and campaign committee. In a presidential contest against fundraising giants like Bush, that may be a pittance, but it proves something: Graham isn't just an outspoken politician hoping to boost his name recognition in 2016. No, if Graham—who has an undefeated campaign record—is running for president, he's going to at least influence the primary.

Graham is, in a sense, the party's old-school foreign policy conscience, constantly trying to remind his colleagues about threats to homeland security and supporting the military. He's not a front-runner, and likely won't become one, but he could still dominate the debate about the country's place in the world in the next year and a half.

"Lindsey Graham is not that well-known, obviously," McCain said. But, he added, "he will be well-known before this is over."

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