Herman Cain came under intense scrutiny after allegations of sexual harassment hit his campaign Sunday evening, but it didn’t seem he needed to worry too much about questions from GOP presidential rivals. That all changed Tuesday morning, when a longtime strategist of Rick Santorum called on Cain to give a more forthcoming explanation of the allegations.

“What I would encourage the Cain campaign to do is, if you are the front-runner and you plan to be the nominee, to be forthcoming so that you are vetted, and we don’t get into a situation where you’re our nominee and we find out things after the fact,” said Santorum adviser John Brabender, speaking at an election preview forum hosted by the National Journal, as reported by the Washington Post .

It’s been hands off since Sunday night, with none of the other campaigns responding to the Cain allegations, which were  first reported by Politico. But Brabender’s comments could open the door for other campaigns to demand answers from Cain.

Politico reported Sunday evening that two women had received settlements from the National Restaurant Association after accusing Cain, then the CEO, of sexual harassment. Cain has had conflicting answers since the story broke, and he even refused to give a flat out no when  asked in a PBS interview Monday if he had ever met one of the women in a hotel room during a Restaurant Association conference.

“That I absolutely do not recall. You know, I have no recollection of that,” Cain said.

This is the Santorum’s campaign second hit on Cain in recent days. Last Friday Santorum released a web ad attacking Cain on his varying and seemingly conflicting statements on abortion. Brabender seemed to suggest abortion would remain an open issue of attack for the Santorum campaign.

“As part of this process, it’s a fair thing for people to ask campaigns to specify when they say one thing here and another thing here,” Brabender said. “We’re still waiting for clarification from the Cain campaign. We’re as confused as ever.”

In last week’s Des Moines Register poll, Santorum came in with only 5 percent support, but he has an intense campaign schedule in the Hawkeye State, planning to hit all 99 counties by Wednesday, in the hope that hard work and a focus on such social conservative issues as abortion will help him gain traction in the state.