Rep. Warren Davidson, R-Ohio, suggested in a post on X that Sen. Darline Graham, R-S.C., is an "ally" of the "swamp."
Graham, who finished the Aug. 11 South Carolina GOP special U.S. Senate primary in first place, will go head-to-head against second-place finisher Rep. Ralph Norman, R-S.C., in an Aug. 25 runoff.
"Ralph Norman will work to drain the swamp. The swamp wants allies not adversaries. The swamp appointed an ally. These are the stakes in South Carolina," Davidson wrote in the Monday social media post.
South Carolina Gov. Henry McMaster appointed Graham to fill the seat of her late brother, Sen. Lindsey Graham, last month in the wake of the senator's death.
Fox News Digital attempted to reach out to Sen. Darline Graham's campaign on Monday.
MARK LYNCH ENDORSES RALPH NORMAN AS CONGRESSMAN HEADS INTO RUNOFF AGAINST DARLINE GRAHAM
President Donald Trump, who urged Graham to run and endorsed her prior to the special primary, is continuing to back her heading into the runoff contest.
"SOUTH CAROLINA: GET OUT AND VOTE FOR DARLINE GRAHAM ON TUESDAY, AUGUST 25TH. DARLINE HAS MY COMPLETE AND TOTAL ENDORSEMENT — SHE WILL NEVER LET YOU DOWN!" the president declared in an Aug. 14 Truth Social post.
DARLINE GRAHAM DETAILS HOW SHE'D FORGE OWN PATH IN SENATE WHILE CARRYING ON BROTHER LINDSEY'S LEGACY
The president's post included an image of a post on X in which Rep. Russell Fry, who placed third in the South Carolina special GOP U.S. Senate primary, urged those who backed him in that contest to vote for Graham during the runoff.