Former Republican presidential candidate Newt Gingrich is setting a low bar for President Barack Obama's debate performance, saying that he only needs to be "believable" to be re-elected.

The former House Speaker on Friday told MSNBC that GOP hopeful Mitt Romney would need a "very strong debate" to even have a chance at the White House.

"They're whistling past the graveyard," Gingrich said of the Romney campaign. "I think that everybody I've talked to agrees that he's had two and a half very tough weeks. I do agree, I think they started with the Clinton speech [at the Democratic Convention] and then they got compounded by all the other stuff that happened."

"I do think in all fairness to Romney, when it got to be a crisis in Florida [during the Republican primaries], he was very good in the debates," he explained. "That better be the Romney that goes to the debate with Barack Obama."

"It has to be a campaign of contrast, not a campaign of attack," Gingrich added. "Part of the contrast has to be disarming the president because if the president's believable -- this is where Clinton was so good -- if the president is believable at the end of the first debate, there's a very high likelihood that he going to get re-elected."

In a memo to surrogates on Thursday, Romney senior adviser Beth Myers tried to set very low expectations for Romney's performance at the debates.

"President Obama is a uniquely gifted speaker, and is widely regarded as one of the most talented political communicators in modern history," Myers wrote, insisting that Obama had a "significant advantage" because of his "ample rhetorical gifts."

Watch this video from MSNBC's Morning Joe, broadcast Sept. 28, 2012.