With five days to go until the Iowa caucus, all six contenders for the Republican presidential nomination are making their rounds in small towns across Iowa. Newt Gingrich's poll numbers  continue to fall  in the Hawkeye state, opening up the possibility for another candidate to overtake the lead. Hopefuls who have stuck it out since the beginning –  like Rick Santorum and Ron Paul –  have  experienced a recent uptick in popularity. Pat Blank, senior news producer for Iowa Public Radio, explains why Gingrich has seen his numbers decline, and who Iowans are likely to caucus for. Bill Adair, editor of Politifact, takes a look at the ad war in Iowa, where an unprecedented $10 million has been spent on TV and radio ads  just this month.