Washington — Republican Clay Fuller won Tuesday's runoff election to replace former Rep. Marjorie Taylor Greene in Georgia's 14th Congressional District, CBS News projects, padding the House GOP's razor-thin margin by an additional vote. 

Fuller beat Democrat Shawn Harris in the northwest Georgia district after the two advanced from a crowded field of candidates in a special election on March 10.

Fuller won by fewer than 12 points, a 25-point swing from when President Trump won the district by 37 points in 2024, making it the biggest swing in a House special election during Mr. Trump's second term. Greene won the district 29 points in 2024 and 31.8 points in 2022.

Fuller
on Wednesday called his win "a dominating performance,"
saying Democrats should be concerned about the campaign money spent on Harris who he said wasn't "even competitive in this special election."

"We're really proud of how we did," he told CBS News chief Washington correspondent Major Garrett on "The Takeout."

Greene said Tuesday's margin shows voter backlash against Mr. Trump. In a post on X, she wrote that the district was never in danger of flipping, "but the results speak for themselves."

"Trump flipping MAGA from America First to America Last, covering up for the Epstein files, and betraying key campaign promises of no more foreign wars has been the best help for the Democrats. Sad!" she wrote.

When asked about Mr. Trump and his conflict with Greene, Fuller told CBS News his constituents aren't concerned about the past and that he's looking forward to supporting the president and his "America First" agenda in Washington.

"The voters are concerned about sending me up to Capitol Hill to make sure that I'm a fighter for President Trump and bringing back those manufacturing jobs to the district," Fuller said. "They want a fighter up there for the future to have their back and have President Trump's back."

A candidate had to receive a majority of the vote in March to avoid a runoff. Harris, a retired Army general, pulled in more votes than Fuller, a district attorney, in last month's contest as Republicans split their votes among several candidates. Though it injected a jolt of optimism into the possibility that Democrats could pull off a major upset, Harris faced long odds in a one-on-one matchup in the reliably conservative district.

The outcome gives House Republicans — who had a 217 to 214 majority leading up to Fuller's victory — another seat as any one defection has threatened to derail their legislative agenda in recent months. Another seat is held by an independent, who switched his party affiliation in March, but still caucuses with Republicans. Fuller's win bumps up Republicans' margin to two votes. 

Fuller, who had Mr. Trump's backing, will serve out the remainder of Greene's two-year term, which ends in January 2027.

Greene resigned in January after a falling-out with Mr. Trump.

Mr. Trump celebrated Fuller's win in a Truth Social post Wednesday, calling him "a very large improvement over his deranged predecessor."