DURHAM,N.C. – It’s the kind of election that doesn’t normally draw much interest: A primary for district attorney, where the only people in town who know much about the candidates are those who work at the courthouse.

That’s not the case this year in Durham, where rape allegations against members of Duke University’s lacrosse team have likely turned what might have been a low-key election into a referendum on the performance of incumbent Mike Nifong.

“I’m sure that after all this is over, people will say that I won because of how I handled this case or I lost because of this case,” said Mr. Nifong, who was appointed to the office last year and is seeking election for the first time. “But no one will ever know.”

The winner of Tuesday’s Democratic primary vote between Mr. Nifong, Freda Black, and Keith Bishop will likely be the next district attorney since no Republicans are running. If no candidate wins at least 40% of the vote, the top two will advance to a May 30 runoff.

Even if Mr. Nifong loses, he will remain in office until January, allowing him to keep pursuing his case against two indicted players. He has said he does not intend to step down early if he loses.

“Knowing that you’re lame duck, in a way it would free you up to do exactly what your conscience dictated – which is what you should be doing all the time,” said Garry Frank, the district attorney for Davidson, Alexander, and Iredell counties, about 90 miles west of Durham. “The duty of a prosecutor is to ignore any political group … and just make your call based on the law and the evidence.”

For more than 20 years, Mr. Nifong was an assistant in the Durham district attorney’s office, and fellow attorneys say he was comfortable in that role – practicing law while being able to leave at the end of the day to watch his son play baseball.

Mr. Nifong never expressed any interest in the top job before he was elevated to last year to fill the term of Jim Hardin, who was appointed to a judgeship, said Woody Vann, an attorney who has known Mr. Nifong for 25 years in this city of some 210,000 residents.

Mr. Frank said it’s rare for voters outside the legal community to know much about their district attorney. Contests frequently hinge on voters picking a name on the ballot that they recognize from newspaper articles or yard signs.

“The people who are what you would consider to be active in the community and should be up to date with people who hold (leadership) positions – even they don’t know who their D.A. is,” Mr. Frank said.