Darline Graham's 'embarrassing and inexcusable' national security stumble spotlights break from late brother

Darline Graham's admission that she was not well-versed on Taiwan is drawing scrutiny days before South Carolina's GOP Senate runoff, putting the Trump-backed candidate's national security credentials at the center of her closing fight against Rep. Ralph Norman.

"I tripped up on one question last night, regarding Taiwan. I don't speak politician. I was just honest. Of course, Taiwan is our friend. But I think people in South Carolina are more worried about boys in girls sports," Graham said during an appearance on "Hannity."

"I did say, several times, that China is our enemy, a military and economic threat to the United States."

"I'm not a politician. I don't speak politician. I was just honest, and I think that's a foreign concept in politics."

"I'm sorry, but respectfully, even accounting for her being new to the job, this is embarrassing and inexcusable. China's threat toward Taiwan is a bit of a big deal, especially -- it would seem -- for a member of the U.S. Senate," wrote Heritage Foundation President Kevin Roberts.

South Carolinians "can't afford a grace period for on-the-job training while China buys up farmland near military installations and sends spy balloons over our state," Norman said in a statement.

"I'd expect at least mild curiosity rather than shrugging indifference," said [NSI senior fellow] Nelson.

"This is disqualifying in my opinion," wrote Clay Travis.

Caption: President Donald Trump wants to see the late Sen. Lindsey Graham's sister, Darline Nordone Graham, be appointed to his vacant seat in the Senate to act as caretaker for the remainder of his term.

Video credit: South Carolina ETV -- Aug. 18.