JOHNSTON, Iowa - Rick Santorum got his biggest endorsement yet at a small hotel here: Iowa Secretary of State Matt Schultz. 

Calling it the "best day of the campaign," he said he is "committed to Iowa" and the campaign is beginning to "pick up that critical momentum," despite his low poll numbers.   "People have asked me, 'Why haven't you started to catch on?' And I say, 'Well you haven't been in Iowa for the last week or so because we are definitely picking up momentum in the state of Iowa and across this country.' We feel it coming," Santorum told a crowd of more than 50 people at the Stoney Creek Inn here.

During the previous election cycle, Schultz endorsed Mitt Romney, a fellow Mormon, and Santorum said the endorsement was "a great reaffirmation of the work we've done."

When asked why he went with Santorum over Romney this time, Schultz said it was "really not a reflection on any of the other candidates in the race. This is a reflection of who Rick Santorum is."  

Schultz said he spoke with Romney about an endorsement, as well as several other candidates, but still went with the former Pennsylvania senator.  "I had a conversation with Gov.  Romney like I did with many of the candidates and I enjoyed that conversation with him, but again I'm just glad to be supporting Rick Santorum," Schultz said, adding that he was "asking all Iowans to give him a second look."    

Santorum has been barnstorming the state, campaigning the hardest in a state that usually rewards candidates who spend time here. But Santorum's hard work hasn't paid off in the polls. In the ABC News-Washington Post poll released this week, he only received 7 percent support of likely caucus-goers, but he said that it's only tireless campaigning not advertising that will bring victory Jan. 3.  

"I know there are a lot of candidates doing a lot of television advertising and I've learned from day one from Matt's campaign and from talking to folks out here, you can't buy Iowa, you've got to earn Iowa and we'll see that," Santorum said.  "I really believe that."  

Santorum was asked about Newt Gingrich's surging campaign, despite spending much less time in the state than he has. He called Gingrich a "friend" and someone he has "a lot of respect for."

But earlier in the event he drew a distinction between himself and his opponents, making a clear contrast between his family life and Gingrich's past, which includes three marriages and admitted infidelity.   "I'm consistent. My record isn't Swiss cheese, it a solid block of cheese," Santorum said.  "I've been married 21 years, got seven kids, go home to my wife and kids at night and coach little league. It's not a lot of bling."  

Schultz was asked about the other statewide politicians and conservative leaders who have stayed on the sidelines and not yet endorsed, even though the caucuses are 25 days away.  "This is what I would say to congressman [Steve] King and [businessman] Bob Vander Plaats:  It's time to endorse Sen.  Santorum," Schultz said to cheers.

Santorum then quipped, "I have nothing to add to that statement."