A new poll of likely GOP primary voters in South Carolina shows businessman Mark Lynch vaulting past Sen. Lindsey Graham when voters learn about both candidates' records, a result that signals deep vulnerability for one of Washington's most entrenched incumbents heading into the May primary.
The poll, conducted by Pulse Opinion Research for the Lynch campaign and provided exclusively to Breitbart News, surveyed 1,000 likely Republican primary voters from March 11 to 17, with a margin of error of 3.1 percent. On the initial ballot, Graham leads Lynch 41 percent to 21 percent, with third candidate Paul Dans at 11 percent and 22 percent unsure.
Those numbers flip on the informed ballot. According to Breitbart, once voters hear about the candidates' actual records, Lynch jumps to 34 percent while Graham collapses to 23 percent. Dans holds at 11 percent, and 26 percent remain unsure.
An 18-point swing isn't a polling quirk. It's a portrait of an incumbent surviving on name recognition alone.
The polling memo accompanying the results did not mince words:
"Lindsey Graham is in real trouble in this solidly pro-Trump primary."
The memo went further, arguing that the large undecided pool and Lynch's alignment with the base on border security and America First issues position him to win the nomination and the seat. Mark Mitchell, the head pollster of Rasmussen Reports, reinforced the point in even starker terms:
"I've polled quite a few races like this in the '26 cycle and Lindsey Graham is one of the weakest incumbents I've seen."
Mitchell also noted that despite Graham's massive name ID advantage, Lynch takes a clear lead on the informed ballot, calling it "a huge opportunity."
Consider what that means in practice. Graham has served in the Senate for over two decades. He has near-universal name recognition in South Carolina. And the moment voters are given any comparative information about his challenger, they abandon him by double digits. That is not the profile of a senator with a loyal base. That is the profile of a senator whose base has been waiting for a viable alternative.
President Trump's approval rating among the poll's respondents sits at 72 percent, with 41 percent strongly approving. This is the electorate Graham must navigate, and the terrain is not friendly to his brand of Republicanism.
Trump has endorsed Graham, doing so early in the race. But according to the Breitbart report, he has not done much with Graham since then on the campaign trail. The endorsement exists, but it does not appear to be an active partnership. Whether that changes as the primary approaches remain to be seen.
Trump's own history with Graham is worth remembering. Back during the 2016 campaign, Trump said Graham "could not even win a dog-catcher race in South Carolina." The two have since found common ground on various issues, but the relationship has always carried a transactional quality that South Carolina voters understand well.
Lynch has already spent north of a million dollars on the race, and sources familiar with his plans say he intends to spend at least another $3.5 million over the next two months leading into the primary. That kind of money in a state like South Carolina, deployed against a wounded incumbent, can reshape a race entirely.
Graham appears to recognize the threat. South Carolina sources told Breitbart News that the senator has launched attack ads against Lynch on television in the state. When an incumbent with decades of built-in advantages starts running attack ads against a challenger most voters are still learning about, it tells you everything about the internal polling his own team is seeing.
Incumbents who feel safe ignore their challengers. Incumbents who feel threatened try to define them before voters can decide for themselves. Graham chose the latter.
The gap between the initial and informed ballots is the most important data point in this entire survey. It tells a story that goes beyond one Senate race in one state.
Republican voters across the country have spent the last decade sorting themselves. They know what they want: candidates who fight on border security, who reject the instinct to cut deals that sell out conservative priorities, and who align with the America First agenda not as a slogan but as a governing philosophy. Graham has spent years trying to straddle the line between the old Republican establishment and the new populist energy. That act has a shelf life, and the informed ballot suggests it may have expired.
When voters learn who Lynch is and what he stands for, they move. When they learn more about Graham's record, they leave. The polling memo summarized it plainly:
"When South Carolina Republican voters learn the candidates' records, they shift sharply to conservative challenger Mark Lynch. With a large undecided pool and strong Trump alignment on border security and America First issues, Lynch is well-positioned to win the nomination and the seat."
Two months is a long time in a primary. Graham has institutional advantages, donor networks, and the machinery of a career politician who has survived tough cycles before. None of that should be dismissed.
But the fundamentals favor the challenger in a way that rarely happens against a sitting senator. A 22-percent undecided bloc on the initial ballot means the race is still forming. Lynch has the money to introduce himself on his own terms. And every data point in this poll suggests that when voters meet him, they like what they see.
Graham's problem is not that he's unknown. It's that he's known too well.
