Newly sworn-in Sen. Darline Graham, who took over brother Lindsey Graham’s South Carolina seat after his sudden death last month, is facing criticism from Republicans and Democrats alike after admitting she is “not that informed on national security” during a debate.

Graham, 62, stumbled over a question about the U.S. position on Taiwan and the South China Sea during the Republican runoff debate Tuesday evening, declining to answer the question and instead admitting she was not well-read on the matter.

“I’m just going to be honest here, I’m not that informed on national security, so,” Graham responded. “But I do support the military.”

Graham, who was appointed, at President Donald Trump’s prodding, to her brother’s seat in South Carolina after he died in July, has no formal political experience but is hoping to retain her position. However, several Republican politicians raised alarm at her casual ignorance.

“Lindsey Graham was well informed on the United States’ national security. Darline Graham admits she’s not. This is not something you inherit. And it’s critical in the U.S. Senate,” former South Carolina Gov. Nikki Haley wrote on X.

Adam Morgan, a former South Carolina state lawmaker, called it a “stunning debate flop” and said Graham’s response “reveals she can’t answer basic national security questions.”

Jack Posobiec, a prominent MAGA political commentator, wrote on X: “What in the world…” in response to Graham’s answer.

Graham’s answer to the national security question reportedly generated gasps and boos from audience members, the New York Times reported.

Her response stood in stark contrast to her brother’s hawkish foreign interventionist attitude. Lindsey Graham was well known for advocating for stronger U.S. alliances and more active military presence abroad. He was a staunch supporter of Ukraine in its years-long fight against Russia and cheered for strikes against Iran.

On Taiwan, Lindsey Graham had made it clear that the U.S. had a direct security interest in protecting Taiwan’s democracy. He led the 2022 senior congressional delegation on a trip to Taiwan.

Democrats seized on the flub to decry Graham as too inexperienced to hold onto her seat.

Dr. Annie Andrews, the Democratic nominee in the Senate race, wrote on X that “South Carolina deserves better.”

“Darline Graham Nordone is asking for six years as South Carolina’s senator — during wartime — yet has the gall to tell voters ‘national security isn’t my thing,’” Andrew wrote.

Jon Cooper, a Democratic strategist, called the moment “painful to watch” and said Graham was “NOT the brightest crayon in the box.”

When asked for comment on Graham’s debate answer, a spokesperson for the South Carolina senator pointed to her comments in the spin room after the debate.

Graham told the Post and Courier reporter Nick Reynolds that South Carolinians are “worried about their pocketbooks more than they’re worried about the South China Sea, quite honestly.”

Tuesday’s debate was part of the runoff election between Graham and Rep. Ralph Norman, both of whom are vying for the Republican nomination for South Carolina senator.

The special election takes place on August 25. The winner will face off against Andrews in November.