Detroit ? A prosecutor launched an investigation Friday into allegations that Mayor Kwame Kilpatrick lied under oath about an affair with his top aide. Some political observers are questioning whether the popular yet polarizing figure should stay on the job.

“Can he? Yes. Should he? That’s his call,” University of Nevada-Reno political science professor Eric Herzik said Friday. “But if you are being prosecuted, your ability to run the city is incredibly compromised.”

Others believe Kilpatrick could fight perjury charges and still fulfill his mayoral duties. Victoria Mantzopoulos, chair of the political science department at the University of Detroit-Mercy, said it depends on the political machine he has around him.

“I think he can work through it,” Mantzopoulos said. “I’ve heard people ask that he resign. I think that is more on the issue of the affair as opposed to the true ability to continue in his role.”

Wayne County Prosecutor Kym Worthy said Friday that her office would investigate reports that Kilpatrick and Chief of Staff Christine Beatty exchanged romantic text messages in 2002 and 2003, despite testifying in a trial last summer that they did not have a physical relationship then.