Much has changed for Santorum, including the scrutiny By NBC's Andrew Rafferty ALTOONA, Iowa -- While the cities and towns of Rick Santorum's campaign stops in Iowa are the same as they were in the fall, everything else is drastically different for the candidate who is now surging in the polls. The images of the former Pennsylvania senator speaking to half-empty rooms were replaced on Monday night with ones of him standing behind the counter of The Pizza Ranch -- with a bull horn and a message that media outlets from as far away as Japan were present to cover. And the questions changed -- from inquiries why his candidacy isn't resonating with Republican voters, to whether he thinks he'll top front-runner Mitt Romney in tonight's caucuses. "You light that spark," Santorum told Iowans. We'll get it going again in New Hampshire, we'll get it going again in South Carolina. But the level of scrutiny has changed, too. One example: The steady stream of questions Santorum faced regarding robocalls that have blanked the state just one day before the caucus. A voter on Monday asked Santorum to clarify his stance on the 2nd Amendment, after the voter received a call that stated Santorum would not stand up for gun owners. The candidate answered by touting his record with the National Restaurant Association, and saying his entire family own guns. Also in response to the robocall, the campaign sent out a fundraising appeal with the subject line "your blood will boil," citing various robocalls attacking his record. Donations will are needed to "make sure no one is deceived by these lies," the email read. And he's had to defend his past endorsements as well. Recently, he has been challenged in town hall meetings about his backing both of Arlen Specter in 2004 and Mitt Romney in 2008. His support for Specter, Santorum replies, helped get conservative justices on the Supreme Court. And he contends Romney was a better conservative alternative compared to John McCain during the last Republican presidential primary. The blasts against Santorum began with the first shots being fired from Texas Gov. Rick Perry last week over his record on earmarks. But on the trail, Perry's attacks have not seemed to bother caucus-goers the way Santorum's endorsements have. It is a small warning sign for a campaign that has enjoyed more than a week of record crowds, enthusiasm, and fundraising. And with so much going right, Santorum has not been overly concerned with the shots he knew would accompany a rise in the polls. When asked by NBC News if the there is any concern the negative attention could hurt his campaign -- the same way similar attacks brought down Newt Gingrich's poll numbers -- he said: "I think we have a great record, and I'm willing to go out there and compare it with anyone in the race."