Iowans might feel a bit overwhelmed by the choices for next Tuesday’s Republican caucuses for the GOP presidential nomination, but one independent group has begun running radio ads insisting that there is still room for one more choice. Calling itself “Sarah Palin’s Iowa Earthquake,” the group will target specific markets in Iowa asking voters to line up behind the Republican Party’s most prominent non-candidate, and other ads will apparently follow:

Can Iowans caucus for Palin at this late date? Sure. Unlike primary states, there is no “ballot” in the legal sense at caucuses. Attendees can write in names on the list of candidates they receive at the caucuses, and those votes will count. Of course, without Palin on the ballot and not officially in the race, not too many caucus-goers may choose to vote for her. If enough are dissatisfied with the current choices, though, she might be a handy code for None of the Above — and might get some significant level of support if the ads prompt enough Iowa voters to consider this as an option.

If so, who does that hurt most? Probably not Mitt Romney, whose base of support doesn’t have a lot of overlap with Palin’s. Newt Gingrich rose in the polls mainly on Tea Party support, so he’d be likely to feel the sting a little more, especially for those who backed Gingrich because he looked like the only viable alternative to Romney or Ron Paul. Paul might lose a little of his more recent support, but he’s going to get hurt more over his old newsletters and the vetting of his foreign-policy kookiness. It may end up hurting the candidates in the second tier struggling for an Iowa miracle — Rick Santorum and Michele Bachmann. That’s assuming, of course, that it has any impact at all.

Let’s take a look at all five. The first two spots focus on the need to clean up crony capitalism:

The third goes after the three Iowa frontrunners, using quotes from Romney, Paul, and Gingrich as a springboard to get voters to draft Palin:

The final two use the audio from an old Ronald Reagan ad, “Bear in the Woods”: