COLUMBIA, S.C. - The night of his victory in South Carolina's Democratic primary, U.S. Senate candidate Alvin Greene didn't have much to say. Asked how he managed to defeat a four-term lawmaker who the party establishment figured would cruise to a victory, the mysterious Greene had no insights.

Instead, the 32-year-old unemployed military veteran repeated the same flat statement Tuesday about the importance of creating jobs and cutting down on the state's high jobless rate.

Now, thanks to his shocking win, he has the attention of state and national Democrats who also found out he faces a felony obscenity charge. After the Associated Press reported that on Wednesday, the leader of the state Democratic Party said she asked Greene to withdraw from the race against Republican Sen. Jim DeMint.

Greene refused.

"The Democratic Party has chosen their nominee, and we have to stand behind their choice," Greene told a reporter at his Manning childhood home, which he shares with his father. "The people have spoken. We need to be pro-South Carolina, not anti-Greene."

Greene, who did no fund-raising and had no ads or website, had been considered such a long shot that neither his opponent nor the media bothered to check his background.

Court records say he was arrested in November and charged with showing obscene Internet photos to a University of South Carolina student, then talking about going to her room at a university dorm.

On Thursday, the No. 3 Democrat in the U.S. House called on federal authorities to investigate how Greene won the primary.

"Here is Alvin Greene, unemployed, he goes into the Democratic headquarters and pays $10,000. That's no little bit of money for an unemployed person," House Majority Whip Jim Clyburn of South Carolina said. "This guy, who is he? Where did he come from?"