The survey, taken between November 11-13, shows Cain in a statistical tie with Gingrich and Romney close behind in 3rd. The poll breaks down candidate preference into hard support (definitely backing a candidate), moderately hard support (probably backing a candidate) and leaners.
Including all three categories, Cain leads the field with 20 percent, but is in a statistical dead heat with Gingrich, who gets 19 percent. Romney gets 14 percent.
Michele Bachmann and Ron Paul are tied for 10 percent, Rick Perry gets 5 percent, Rick Santorum 4 percent, Jon Huntsman 2 percent and Gary Johnson 1 percent.
Some 13 percent were undecided and 1 percent refused to answer. There were 501 phone interviews taken Nov. 11 to 13 of likely GOP caucus-goers.
The numbers generally comport with national surveys, which have been showing Cain, Romney and Gingrich in various positions in the lead.
A Des Moines Register poll of Iowa, which is considered the yardstick, showed Cain and Romney in a virtual tie, just before sex harassment allegations against Cain from the 1990s were reported by POLITICO and then by other reporters.
But the subsets of the Polling Company survey reveal just how fluid things remain heading into Jan. 3.
Cain has 9 percent of voters "definitely" backing him, while Romney and Gingrich have 8 percent "definitely." Paul has 7 percent "definitely," while Bachmann has 4 percent in that category.
An extremely fluid race to be sure.