Sanford's secret trip to Argentina. The married Republican governor left the state for Argentina for five days while his staff, the lieutenant governor and his security team did not know where he was. Some lawmakers argue Sanford abandoned the state and job; that, they say, is misconduct serious enough to warrant impeachment.
Misuse of state airplanes. State law bars any use of state planes other than for official business. Sanford, according to state documents, used a state plane to ferry family members and to attend political functions, possible violations of state law.
Using expensive airfares on foreign trips. State law requires the use of the most economical travel available. Sanford used more expensive airfare, according to state documents.
Failure to disclose private plane trips. The Associated Press reported Sanford accepted 35 rides on private planes that he did not disclose in his state ethics report, a possible violation of state law. Questions have since arisen about whether Sanford should have paid federal taxes on those plane trips.