(RNN) - After lackluster polling, Sen. Lindsey Graham, R-SC, is dropping out of the presidential race, it was announced Monday.
Graham's message has not resonated with Republican voters. In the five Republican debates, Graham has been on the "undercard" debate with other candidates whose poll numbers are low.
Graham tussled with Donald Trump earlier in the year after the billionaire read Graham's phone number at a campaign event that was broadcast live on the 24-hour news networks.
As a response, Graham made a YouTube video on ways to smash your phone.
Graham announced his bid for the Republican nomination June 1 near his hometown of Seneca, SC. His campaign was notable for his heavy emphasis on foreign policy and advocating a tough approach toward the Islamic State with American troops on the ground.
"Four months ago with the very first debate I said any candidate that did not understand that we need more American troops on the ground in Iraq and Syria to defeat ISIL was not ready to be Commander and Chief," Graham said in the video. "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 out homeland."
His downfall came despite support from a previous Republican presidential nominee with hawkish views, Sen. John McCain, who ran unsuccessfully against President Barack Obama in 2008.
Graham was not afraid to attack other candidates for what he considered a weak plan to combat terrorism. His most frequent target was the Tea Party faction of the Republican Party and specifically Kentucky Sen. Rand Paul, who is also running for the nomination.
Graham himself was a target of criticism from other Republicans for his willingness to work with Democrats. On Sunday evening, Graham said in an interview that he would compromise with Hillary Clinton if she won the presidency - though he stated he didn't want the former Secretary of State to win.
Graham has served in the Senate since 2003, succeeding Strom Thurmond. Graham was elected to the U.S. House of Representatives in 1995 and served in the House until his election to the Senate. Before that, he served two years in the South Carolina House of Representatives.
He is up for re-election for his Senate seat in 2020.
Graham's campaign suspension comes after former Texas Gov. Rick Perry, Wisconsin Gov. Scott Walker and Louisiana Gov. Bobby Jindal withdrew earlier in the year.
On the Democratic side, former Virginia Sen. Jim Webb, former Rhode Island Gov. Lincoln Chafee and Harvard law professor Lawrence Lessig are no longer in the race.