"These prominent local leaders who support Marco's conservative vision for this country will be helping to set the record straight in their communities," the campaign wrote in a press release Monday, noting that "millions will be spent on false attacks against Marco."

In New Hampshire, Rubio is battling with New Jersey Gov. Chris Christie for second place in state-level polls. The two establishment-friendly candidates sparred during the sixth GOP primary debate last week, and have since been going at it on the campaign trail. Christie told a crowd in Iowa Monday he's fond of the Florida senator, but worries about nominating a candidate with the same level of experience that then-Sen. Barack Obama had in 2008.