Newt Gingrich promises to run positive campaign

One day after engaging in a round of testy exchanges with rival Mitt Romney, Republican presidential candidate Newt Gingrich is instructing his staff to keep his campaign positive.

Gingrich sent a letter to his staff, consultants and campaign surrogates Tuesday saying, "We will run a positive campaign focused on our country's future."

Gingrich said that the public deserves a "respectful and constructive" campaign, adding that "It is critical the Republican nominee emerge from this primary campaign un-bloodied, so that he or she can make the case against President Obama from a position of strength."

The candidate said his campaign will not run any negative advertising, and he asked his surrogates not to contribute to any super PACs that run negative ads against other Republicans. He also urged them to avoid initiating any attacks on Republican candidates themselves.

In a speech in New Hampshire on Monday, Gingrich said he would "publicly disown" any super PAC who attacked his Republican rivals on his behalf, CBS News/ National Journal correspondent Sarah Huisenga reports.

Romney has also promised to avoid "outrageous" comments about his GOP rivals, but both Romney and Gingrich yesterday took swipes at each other. After Romney called on Gingrich to return the millions he made working for Freddie Mac, Gingrich attacked Romney for "bankrupting companies" when he led the private equity firm Bain.

Gingrich addressed yesterday's verbal jousting in his letter to his staff and supporters, saying, "I have refrained from launching attacks on my Republican opponents, though I have reserved the right to respond when my record has been distorted. On Monday this occurred when Governor Romney and I engaged in what in diplomatic circles is called 'a frank exchange' over our respective records in the private sector."

Gingrich applauded Romney for also promising to avoid negative attacks.