Chris Cillizza of The Washington Post suggests that Mark Sanford's AP interview today, in which he admitted to non-line-crossing encounters with additional women and took other trips to see Maria Belen Chapur, has damaged his prospects of staying in office.

For one thing, state Attorney General Henry McMaster, who'd been talking down the idea of an official investigation, now wants one.

"In light of the governor's disclosure of additional travel today, I have requested that SLED conduct a preliminary review of all Governor Sanford's travel records to determine if any laws have been broken or any state funds misused," McMaster said in a statement.

Earlier today, state Sen. Vincent Sheheen, a Democratic candidate for governor, called for Sanford to resign.

It's not clear to me how Sanford, by giving interviews calling Chapur his "soul mate," hopes to reconcile with his wife. Her forgiveness has seemed to emerge in the past couple of days as a key to his staying in office, in some eyes.

But the latest Insider Advantage poll, conducted last night, shows half of South Carolinians want Sanford to stay in office.

Among the 949 registered voters surveyed Monday night, 49.8 percent said Sanford should remain governor, compared with 41.4 percent who said he should resign. The remaining 8.8 percent had no opinion.