Newt Gingrich brushed off his slide in the polls Thursday, ascribing the shift to the negative ads against him and claiming his campaign still has the juice to attract a "tremendous response" in Iowa.

The former House speaker, in an interview with Fox News, vowed to stay positive despite falling off the wagon several times in recent days. He appealed to Iowans to make a statement against negative campaigning by supporting his "big solutions" candidacy next Tuesday.

"Anybody who has eight or nine million dollars of negative advertising, much of it false, thrown at them is going to slide for awhile," Gingrich said. "I'm frankly barnstorming Iowa making the case that they shouldn't vote for people that have been running the negative ads. This is a chance for Iowans to say to the country we are sick of consultant-driven negative politics. The stakes are too big."

Gingrich himself has strained to keep a strictly positive tone. After weathering repeated attacks from Ron Paul, he said in an interview earlier in the week that Paul's views are "totally outside the mainstream of virtually every decent American"...