Update September 11:
The Post and Courier has added an expanded story on the call for Sanford to step down.
The S.C. GOP has also posted its full letter online, perhaps most interestingly saying: "When we badly need to focus on job creation, economic development and other reforms, your actions have led to an atmosphere that makes it impossible for you to advance our state in a positive manner. Spending the rest of your administration on defense provides fodder for political opponents that damages the Party as a whole and our candidates individually – something I cannot abide in my role as Party Chairman."
The Post and Courier is reporting that the leaders of the S.C. Republican party have voted to call for Gov. Mark Sanford's resignation.
It increasingly appears that the pivotal moment for Sanford's future will come when the S.C. Ethics Commission rules on Sanford's actions.