A top super PAC with ties to the GOP Senate leadership is preparing to roll out a $10 million ad barrage in South Carolina as Republicans look to boost Sen. Lindsey Graham (R-S.C.) in his unexpectedly tight reelection bid.

The Senate Leadership Fund (SLF) will launch its three-week television and radio blitz starting Saturday in an effort to push Graham over the finish line in his race against Democrat Jaime Harrison, who has closed his polling gap with the South Carolina Republican and emerged as a fundraising juggernaut. 

Consecutive polls have shown the Senate race is a statistical tie after Graham enjoyed a double-digit lead earlier this year. And Harrison has flexed his financial muscle, raising $10.6 million in August alone and $2 million in the two days after a poll released last month showed the race deadlocked.

Signs of Harrison’s strength in the race have spurred Democratic groups to jump into the race, with the Democratic Senatorial Campaign Committee (DSCC) last month announcing a seven-figure investment on his behalf and Senate Majority PAC coming in with another $6.5 million.

The surge in Democratic money in the Palmetto State appears to have alarmed Republicans, including Graham, who has taken to Fox News to plead for donations.

“The far-left money spigot has been turned on for liberal lobbyist Jamie Harrison, and now he’s flooding South Carolina with his liberal donors’ funds. Our investment is an insurance policy helping South Carolinians understand Harrison is not the candidate he portrays himself to be – he is a hardcore liberal bought and paid for by his out of state donors who support a radical agenda,” said SLF President Steven Law. 

SLF’s ad buy was first reported by McClatchy and confirmed by The Hill. 

"After weeks of desperately begging for cash, Senator Graham and his allies in Washington are clearly hitting the panic button," Harrison spokesperson Guy King said in a statement. "Jaime is surging in the polls because he will always stand up for South Carolina, and voters see right through Senator Graham's political games."

The GOP is working to protect its 53-47 majority in the Senate as several Republican incumbents face off against well-funded Democratic challengers across the country and the party has scarce opportunities to go on offense outside of Alabama. The party is already sending money to play defense in battlegrounds like Arizona, Colorado, Maine and North Carolina and would likely prefer to not have to devote substantial funds in the traditionally ruby-red Palmetto State. 

But it appears the GOP may have to play at least some defense against Harrison, who, along with Democratic allies, is using his burgeoning war chest to reserve $15 million in ads in October and November, according to McClatchy. The Security is Strength PAC, a super PAC backing Graham, also has $2.2 million in ad time reserved for those months. 

The challenge from Harrison is the toughest Graham has faced after winning his seat in 2002. He coasted to reelection in both 2008 and 2014, though prognosticators still predict he’ll win a fourth term. The South Carolina Republican has emerged as a top boogeyman for Democrats over his close ties to the White House, most notably in 2018 during his high-profile defense of now-Supreme Court Justice Brett Kavanaugh against sexual assault allegations.

The Cook Political Report, a nonpartisan election handicapper, rates the Senate race as “lean” Republican.