A suggestion four years ago by Katrina Pierson, who's now Donald Trump's spokeswoman, that the Sept. 11 attack was an "inside job" is getting attention again.

Pierson, who has raised eyebrows for past comments about Muslims, fetuses and nuclear weapons, tweeted on Sept. 13, 2012: "9/11...An inside job?" Pierson serves as national spokeswoman for Trump's presidential campaign.

The tweet was given new life Monday morning through retweets, as Trump faces questions about blaming President George W. Bush for the 2001 terrorist attack. Her four-year-old message quickly received a torrent of criticism.

Pierson was not affiliated with Donald Trump at the time. In 2012, she was a vocal supporter of Ted Cruz's Senate run in Texas.

Trump revived the 9/11 issue while attacking former Florida Gov. Jeb Bush during Saturday's GOP debate in South Carolina.

"How did he keep us safe when the World Trade Center went down?" Trump said as the audience booed. "I lost hundreds of friends, the World Trade Center went down during the reign of George Bush. He kept us safe? That is not safe."

Trump has since tried to backpedal his comments. But Pierson has, in the past, defended her boss for other statements about 9/11, including his claim that thousands of Muslims in New Jersey cheered the day of the attack.

Pierson has also drawn scrutiny for suggesting she'd wear a "fetus necklace" after her bullet necklace showing support for the National Rifle Association drew attention and arguing that having a nuclear arsenal is meaningless "if you're afraid to use it."