After once surging to the front among Republican presidential candidates, former U.S. House speaker Newt Gingrich has wilted after a barrage of negative ads from his rivals.

Gingrich has been hit repeatedly by personal attacks from former Massachusetts governor Mitt Romney and Representative Ron Paul, who have climbed to the top of the polls in Iowa.

The 2012 presidential campaign begins in Iowa on January 3 with the nation's first nominating contest.

But in an interview Thursday with Fox News, Gingrich said he can still attract a “tremendous response” in Iowa. When a voter asked if he really wanted to be president, Gingrich was clear that he did.

“I think it's my duty as a citizen and as a grandfather to try to help serve my country at a time when I think we're in real trouble.”

Rivals have also attacked Gingrich with verbal jabs.

A few days ago, Romney said the inability of Gingrich's campaign to qualify for the Virginia ballot was like “Lucille Ball at a chocolate factory.” Romney was referring to the comical scene in the 1950s television show I Love Lucy, in which Ball is overwhelmed by a rapid assembly-line procession of chocolates.

Gingrich responded by visiting a chocolate factory in Iowa, where he said he had a chance to make some chocolates.

The latest U.S. poll shows Gingrich in fourth place in Iowa at 14 percent, after once polling as high as 33 percent. He has also fallen in New Hampshire. He is running about even with Romney in the national polls.

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