Unlike some of the other presidential candidates' spouses, Callista Gingrich has not played a very public role in her husband's campaign but recently on her Twitter feed, she re-tweeted two hits at Mitt Romney written by a Gingrich supporter with the Twitter handle @UnitedStates.

"Mitt's 'Money Never Sleeps' photo. I personally don't mind it, but it won't play well in Ohio'' reads one re-tweet  concerning Romney's famous Bain Capital photo from the 1980's.

And the other one, a reference to yesterday's "FOX News Sunday" interview with Romney.

"Poor Romney. He just is a sound bite candidate. Chris Wallace pulled the string from his back, and he spewed consultant apprvd policy #tcot ",  it says.

Gingrich and his campaign have mostly avoided going negative, focusing on what the former Speaker of the House calls  "positive ideas and positive solutions."