DES MOINES, Iowa-Rick Santorum gave a realistic evaluation today on what will happen if he doesn't win next Tuesday or more specifically if he comes in at the back of the pack.

"If I finish dead last behind the pack I'm going to pack up and go home," Santorum said to Iowa talk show host Jan Mickelson on WHO radio today. "I don't think that's going to happen. I think we're gonna be very much in the mix, and I feel very good that we're gonna surprise a lot of people on how we finish."

He added that he doesn't think finishing last is "going to happen." He's been barnstorming the state for months and Monday he said there are three contests being fought in the state simultaneously.

"There's the libertarian primary, which Ron Paul's going to win. Then you've got the moderate primary, which Gingrich and Romney are scrumming for. And you've got three folks who are running as strong conservatives," Santorum said, referring to himself, Michele Bachmann and Rick Perry. "I think if we win that primary we are in very good shape."

He's drawing battle lines where a win over Bachmann and Perry will be a victory for him and a ticket out of Iowa.

He's consistently said the caucuses are all about expectations and he again told Mickelson today, "We have to exceed expectations. And the expectations right now for us are pretty low, based on a lot of the national polls, so I feel like we need to do well," Santorum said. "We need to be right in the mix. Obviously we'd like to win, and our intention is to win it, and we're doing everything we can to try to finish first, and you know, somewhere in that middle of the pack and up we'd feel very, very good, though."

ABC News' Josh Haskell contributed reporting.