Bob Vander Plaats, the Iowa Christian leader who endorsed Rick Santorum just before the candidate surged to success in the caucuses Tuesday night, isn't done yet.

The head of the conservative and religious Family Leader organization told ABC News on Wednesday that he's been making flurries of calls to like-minded faith leaders in New Hampshire and South Carolina to build support for Santorum in those states' primaries over the next few weeks.

Vander Plaats said he had made 12 to 15 calls to "pro-family" leaders in those states on Wednesday alone, but he wouldn't say with whom he's spoken, citing their privacy.

Santorum hovered near last place in Iowa until shortly after Vander Plaats supported him, an endorsement that was marred partially by suspicion that money was involved but which ultimately led to the former Pennsylvania senator's coming in second to Mitt Romney, who led by just eight votes.

"There was this real bubble of support that was just waiting to burst," said Vander Plaats, who called the allegations that he demanded money from Santorum "baseless." "We just needed to put a stamp of credibility or a credibility poke. … So hopefully, we were able to do something like that, and people then took note."

Vander Plaats, who was with Santorum on Tuesday night as some of the caucus results arrived, is now publicly calling for Rick Perry and Newt Gingrich to drop out and support Santorum so that he can face Romney alone in South Carolina, a state with a heavy evangelical population.

"The sooner we can get this to a one-on-one with Mitt Romney, the better for Rick Santorum, because Romney does not want a one-on-one," he said.