Half of South Carolina voters asked whether scandal-plagued Gov. Mark Sanford should stay or go picked "resign" in a poll conducted Thursday by Insider Advantage.

Of those responding to the poll of 917 voters, 50 percent said they were for Sanford's resignation, while 37 percent believed he should remain in office and 14 percent had no opinion.

There have been growing calls for Sanford to step down since he admitted in June to an affair with a woman in Argentina. Since then, additional questions have been raised about his travel spending as governor, hurting his image as a fiscal conservative and leading to investigations into whether Sanford broke the law.

Fifty-four percent of Americans think that South Carolina Gov. Mark Sanford should resign from office following his admission of an extramarital affair and his unexplained five day absence from his duties, according to a CNN/Opinion Research poll conducted June 26-28. Forty-four percent say he should serve out the last 18 months of his term.

"There is virtually no difference between Republicans and Democrats on this matter," says CNN Polling Director Keating Holland. "Fifty-one percent of Democrats and 54 percent of Republicans want Sanford to step down."

Since the initial revelation, Sanford has said that he "crossed lines" with a handful of women other than his Argentinean mistress but didn't have sex with them.

Despite revelations Wednesday about South Carolina Gov. Mark Sanford's infidelity and use of a taxpayer-funded trip to visit his mistress in Argentina, a majority of the state's voters think Sanford is "about as ethical" as most politicians.

Just 18 percent said Sanford was less ethical, according to a poll conducted June 25 by Rasmussen Reports. South Carolina voters apparently do not have high expectations for their elected officials: a third agreed that most members of Congress and governors have extramarital affairs, 42 percent were unsure and just a quarter disagreed.

Rasmussen found a lower number of voters - 46 percent -- saying Sanford should resign than other recent polls. Sixty percent of respondents to a Survey USA poll conducted June 24 believed the governor should step down. In the Rasmussen poll, 39 percent opposed Sanford's resignation and 16 percent were unsure.

We take a bow, as always, to Nate Silver's analysis of polls on his FiveThiryEight.Com site where, digesting two polls about South Carolinians who wanted Gov. Mark Sanford to resign after his admission of an extramarital affair, contrasted them to polls on other "pantsless pols" who had admitted similar indiscretions.

His conclusion: Sanford faces more pressure to resign than many of the others, except for former New York Gov. Eliot Spitzer. But those who want Sanford to step down outnumbered those who wanted to wave good-bye to former Idaho Sen. Larry Craig, former New Jersey Gov. James McGreevey, former President Bill Clinton, Nevada Sen. John Ensign and Louisiana Sen. David Vitter.

Here's the nifty chart that Nate constructed based on polling of other prominent politicians who have strayed from the path:

Although South Carolina Gov. Mark Sanford promised Wednesday to redouble his focus on state issues after admitting to an extramarital affair, three-fifths of his constituents apparently wish he would just go away.

Sixty percent of South Carolina respondents to a Survey USA poll conducted Wednesday said Sanford should resign his office in the wake of his disclosure of his relationship with a woman in Argentina. Just more than a third -- 34 percent -- said he shouldn't resign.

The poll was conducted in conjunction with television station WCSC in Charleston.

Most of the respondents also expressed anger over the two-term Republican governor's week-long disappearance that preceded his confessional news conference. Sanford did not notify the public of his absence or his staff of his whereabouts. This prompted his staff to tell reporters he was hiking the Appalachian Trail, when he was, in fact, in Argentina.