I’m talking about the Michigan debate Eva. It was the turning point. Granted it was two on one (Newt stayed above the fray; turned everyone of John King’s questions back on Obama). The real damage that was done to Rick was done by Romney though.
No, the damage that was done to Santorum was from Ron Paul, and then Romney doubled down on it, but it was the Arizona debate, not the Michigan one.
Gingrich has since signaled that he would pile on the Paul Romney tag team, though.