During last week's visit to Iowa for a GOP debate, I wrote about all of the negative ads being run against Newt Gingrich on radio and television, and the rumblings of how his poll numbers were softening.

We might be starting to see some evidence of that.

Two new polls from Iowa, one from Public Policy Polling and the other from Insider Advantage show Gingrich dropping back in the GOP race in the Hawkeye State over just the last week.

Insider Advantage polled in Iowa on December 12 and had this:

Gingrich - 27%
Paul - 17%
Perry - 13%
Romney - 12%
Bachmann - 10%

The latest poll from Insider Advantage from December 18 now has Ron Paul in the lead and a giant drop in support for Gingrich:

Paul - 24%
Romney - 18%
Perry - 16%
Gingrich - 13%
Bachmann - 10%

What's interesting about the Insider Advantage poll is that the company is run by someone who has close ties to Gingrich - when the December 12 poll came out, I had a number of fellow journalists send me messages that I should ignore that poll because of those ties.

I guess I ask now - if it is biased towards Gingrich, then why is he in fourth this time around?

The other poll out from Iowa right now is from Public Policy Polling, and again people are telling me to ignore this one as well. But let's take a look:

Paul - 23%
Romney - 20%
Gingrich - 14%
Perry/Bachmann/Santorum - 10%

That poll was conducted from December 16-18.  One week earlier, Gingrich was at 22% in that poll in Iowa;  back in early December PPP had Gingrich at 27%.

I will repeat many times in coming months that we shouldn't just blindly trust the polls, but we also shouldn't ignore trends that might develop in some of them.

I want to see more polling information confirming a drop for Gingrich, but all of the negative ads may be having the intended impact in the Hawkeye State, with just two weeks until the Iowa Caucuses - especially since Insider Advantage found Gingrich was still leading in South Carolina, where the airwaves have not yet been flooded with attack ads.

We also should note the good polls for Ron Paul, though some wonder if that is influenced by people who might not actually go to caucus on January 3.