Meanwhile, Mr. Bauer’s camp appears to have been orchestrating pressure for a resignation.

“André Bauer is my client; I’ve been working this since Monday,” wrote Chris LaCivita, a political consultant on Mr. Bauer’s team, in an e-mail message to another Republican political operative that was provided to The New York Times by an opponent of Mr. Bauer. “I need to get this guy (Sanford) out,” he wrote, referring to the governor.

But Mr. LaCivita stumbled into the mare’s nest of South Carolina politics, apparently unaware that he was sending the message to an ally of Mr. McMaster, who has declined to call for the governor’s resignation and said that any investigation of the governor should be free of political motivations.

“On this, I can’t help you,” the recipient, Curt Anderson, a national political consultant, responded. “Henry McMaster has been a friend of mine for almost 20 years.”

Mr. LaCivita said he sent the message outside the context of the lieutenant governor’s official duties.

“This is me professionally seeking information and sources from people I thought I could trust,” he said. “This is completely outside the realm of what the lieutenant governor is doing, which is fulfilling his constitutional duties  something his opponents should follow his example on.”

Mr. Bauer played down the prospect of taking over for Mr. Sanford on the Fox News program “Huckabee” this weekend, saying, “Nobody wants to become governor like this.”

The fight has trickled down to the many local Republican committees at the heart of the party. Forces loyal to Mr. Bauer have found common cause with those angry at Mr. Sanford, increasing calls for his resignation  hoping to put together a rally later this week  while those loyal to the other players have held their ground.