Loeffler and other Republicans are standing firm against calling Bolton or any other witnesses to testify, but she called out Romney for taking a different stand.
"Sadly, my colleague @SenatorRomney wants to appease the left by calling witnesses who will slander the @realDonaldTrump during their 15 minutes of fame," she wrote.
The GOP clash comes on the heels of a weekend New York Times report that Bolton has in his upcoming book details about a conversation with President Donald Trump about withholding military aid to the Ukraine.
Loeffler’s decision to single out Romney comes as she continues positioning herself as a Trump conservative. Romney is known as a moderate and has criticized the president in the past.
Loeffler and Romney were once close friends. She and her husband, Jeff Sprecher, supported Romney’s presidential ambitions.
The couple told Atlanta Magazine in 2013 that they met the then-candidate at a fundraiser and their families grew close.
“We got to know him and his wife, and have been to his house many times and they’ve been to our house,” Sprecher said. “Taking politics off the table, the Romneys are really lovely people, and well intended.”
Loeffler donated $763,414 to Romney’s 2012 campaign, and Sprecher gave another $850,083, according to a review of federal campaign finance records. Sprecher also wrote Romney a $2,300 check in 2007.
Romney has not responded publicly to Loeffler critique.