We’ve been speculating for some time now that, of the candidates battling it out for the GOP nomination, Rick Santorum might be the closest to an early exit barring a strong showing in the Ames straw poll. At Outside the Beltway, Doug Mataconis directs us to a Friday interview where Santorum seems to confirm these suspicions.

On Friday, Rick Santorum suggested he could become the first political casualty of the 2012 presidential race.

Just over two months after his official presidential campaign began, the Republican candidate intimated it could soon end – if he’s not “in the top five” in Saturday’s Ames Straw Poll.

The Republican presidential candidate spoke with CNN Chief Political Correspondent Candy Crowley at the Iowa State Fair in Des Moines.

“I think we have to be in the top five. I mean if we’re eight or ninth – if we’re not in the top five – this tells me that we don’t have the organizational ability to get this thing done,” Santorum told Crowley.

It looks to me like Santorum is actually leaving himself some wiggle room here. After all, there are only nine candidates on the ballot, so shooting for the “top five” isn’t setting the bar very high. Given the demographics of Iowa and the fact that the ultra-Christian conservative Santorum has practically been living there for a year, it might not be that much of a trick. We can assume that Rick should be able to draw more support than Huntsman, Newt and Thad McCotter. At that point he just needs to edge out one more. Cain, possibly?

Another scenario is that one of the stronger performers might have a significant amount of their support drained off by write-in ballots for Rick Perry, allowing Santorum to sneak in to fifth place through the back door. Either way, in a straw poll like this, all sorts of things can happen. Another possibility comes from this odd aspect of the straw poll rules.

Who can vote in the Ames Straw Poll?

Unlike local Iowa caucuses, the Ames Straw Poll is one event that all residents of Iowa and students at Iowa colleges 18 years of age and older on or before November 2012 are invited to attend. Ames is located in the near center of Iowa, making it an ideal location for residents all over the state to travel to. The event is completely sponsored by the Republican Party of Iowa and the ballot includes only Republican candidates; but all Iowans, regardless of party affiliation, are invited.

The planned, deliberate presence of a lot of non-Republicans at the fair this year is already evident. We’ve seen progressive hecklers showing up to cause problems for Tim Pawlenty and Mitt Romney. How many of them are making the trip? All you need is a ticket to the event (and a fundraising dinner) to vote, and if an organized Left wing movement is there you can be sure they’ll be participating. Might they attempt to stuff the ballot box with votes for a candidate perceived to be an easier match-up with President Obama next year?

None of this means that Santorum won’t bow out if he performs poorly, of course. But Friday’s interview could also be nothing more than signs that Rick is looking to lower expectations in the event he finishes poorly. It’s still fairly early for anybody to throw in the towel.